CN101832875B - Progressive cable structure health monitoring method based on cable force monitoring - Google Patents

Abstract

The progressive cable structure health monitoring method based on cable force monitoring is based on cable force monitoring, that is, the cable force of all supporting cables and artificially increased cables is monitored, taking into account the current value vector of the monitored quantity and the initial value of the monitored quantity The linear relationship between the vector, the unit damage monitored quantity change matrix and the current nominal health state vector is approximate. In order to overcome this defect, the present invention provides a method for using the linear relationship to approach the nonlinear relationship in segments, dividing the large interval into Continuous small intervals, the above linear relationship is accurate enough in each small interval, and appropriate algorithms such as multi-objective optimization algorithms can be used to quickly identify support displacement, damaged cables and slack in each small interval search.

Description

Progressive cable structure health monitoring method based on cable force monitoring

technical field

The invention is based on structural health monitoring technology, based on cable force monitoring, adopts a progressive method to identify support displacement, identify damaged cables in the cable system of the cable structure, and identify supporting cables that need to adjust the cable force, and gives specific instructions. The adjustment amount of the cable length belongs to the field of engineering structure health monitoring.

Background technique

Support displacement is a major threat to the safety of cable structures. Similarly, the cable system is usually a key component of the cable structure, and its failure often leads to the failure of the entire structure. Based on structural health monitoring technology to identify support displacement and cable Damaged cables in the cable system of structures is a very promising approach. When the support is displaced, or the health status of the cable system changes, or both occur simultaneously, it will cause changes in the measurable parameters of the structure, such as changes in the cable force, which will affect the deformation of the cable structure or Strain will affect the shape or spatial coordinates of the cable structure, and will cause changes in the angular coordinates of any imaginary straight line passing through each point of the cable structure (for example, the angle of any straight line passing through the point in the tangent plane of any point on the surface of the structure Coordinate changes, or changes in the angular coordinates of the normal at any point on the surface of the structure), all of these changes include the health status information of the cable system, in fact, the changes in these measurable parameters include the health status information of the cable system, Bearing displacement information is included, which means that measurable parameters of the structure can be used to identify bearing displacements, damaged and slack cables.

In order to have a reliable monitoring and judgment of the health status and support displacement of the cable system of the cable structure, there must be a reasonable and effective establishment of the cable structure. The health monitoring system established based on this method can give more credible support displacement evaluation and cable system health evaluation.

Contents of the invention

Technical problem: The present invention discloses a progressive cable structure health monitoring method based on cable force monitoring, which adopts the progressive method and can reasonably and effectively identify support displacement, damaged cables and slack cables for health monitoring.

Technical solutions: Cable-stayed bridges, suspension bridges, truss structures and other structures have one thing in common, that is, they have many parts that bear tensile loads, such as cable-stayed cables, main cables, slings, tie rods, etc., and the common points of such structures Cables, cables, or rods that only bear tensile loads are used as supporting components. For convenience, the present invention expresses this type of structure as "cable structure". During the service process of the cable structure, the supporting system of the cable structure (referring to all load-bearing cables and all supporting rods that only bear tensile loads, for the sake of convenience, this patent refers to all supporting components of this type of structure as It is called "cable system", but in fact the cable system not only refers to the supporting cables, but also includes the rods that only bear the tensile load) will be damaged, and the support of the cable structure may also be displaced. These changes have a great impact on the safety of the cable structure is a threat,

Let the sum of the number of cables and the number of support displacement components be N. For the convenience of narration, the present invention collectively refers to the evaluated cables and bearing displacements as "the evaluated object", and the evaluated objects are serially numbered, and the present invention uses the variable j to represent this numbering, j=1,2,3, ..., N, so let's say there are N objects being evaluated.

According to the reasons for the change of the cable force of the support cable, the change of the cable force of the support cable can be divided into three situations: one is that the support cable has been damaged, such as local cracks and corrosion in the support cable, etc.; the other is that the support cable has no damage. damage, but the cable force has also changed. One of the main reasons for this change is the cable length (called the free length) under the free state of the supporting cable (at this time, the cable tension is also called the cable force is 0). The free length of the cable between the two supporting ends of the cable) has changed; the third is that the supporting cable is not damaged, but the cable structure support has a displacement (the component in the direction of gravity is called settlement), which will also cause Changes in the internal force of the structure, of course, will also cause changes in the cable force. For convenience, in the present invention, the support cables whose free length changes are collectively referred to as slack cables.

Assuming that there are Q supporting cables in the cable system, the structural cable force data includes the cable force of these Q supporting cables, obviously Q is smaller than the number N of the evaluated objects. It is impossible to solve the unknown state of N evaluated objects only by Q cable force data of Q support cables. The present invention increases the number of not less than (N-Q) on the basis of monitoring all Q support cable forces. other monitored quantities.

The other monitored quantities that have been increased by no less than (N-Q) are still cable forces, described as follows:

Artificially increase M ₂ (M ₂ is not less than NQ) cables in the structure, the stiffness of the newly added M ₂ cables can be much smaller than that of any supporting cable in the cable structure, for example, 10 times smaller, the new The cable force of the added M ₂ cables should be small, for example, the normal stress of its cross section should be less than its fatigue limit, these requirements can ensure that the newly added M ₂ cables will not suffer from fatigue damage, and the newly added M ₂ cables Both ends should be fully anchored to ensure that there will be no slack. The newly added M ₂ cables should be fully protected against corrosion to ensure that the newly added M ₂ cables will not be damaged and slack. During the structural health monitoring process, the monitoring This newly increases the cable force of the M ₂ cables. Based on the above-mentioned monitored quantities, the entire structure has M monitored quantities with M (M=Q+M ₂ ) roots, and M must not be less than the number N of evaluated objects.

For the sake of convenience, in the present invention, "all monitored parameters of the structure" are simply referred to as "monitored quantities". Number the M monitored quantities consecutively, and this number will be used to generate vectors and matrices in subsequent steps.

The present invention is made up of two major parts. They are: 1. The method of establishing the knowledge base and parameters required by the health monitoring system of the evaluated object, and the method of evaluating the health status of the evaluated object based on the knowledge base (including parameters) and the strain (or deformation) of the measured cable structure; 2. The software and hardware components of a health monitoring system.

The first part of the present invention: a method for establishing a knowledge base and parameters for health monitoring of an evaluated object. It can be carried out cyclically and progressively according to the following steps:

Step 1: At the beginning of each cycle, it is first necessary to establish or have established the initial health state vector d _o ⁱ (i=1, 2, 3, ...) of the evaluated object at the beginning of this cycle, and establish the initial mechanics of the cable structure Calculation benchmark model A _o (such as finite element benchmark model, A _o is constant in the present invention), establishment of mechanical calculation benchmark model A ⁱ of cable structure (such as finite element benchmark model, i=1, 2, 3, ... ). Except where the letter i clearly represents the step number, in the present invention, the letter i only represents the number of cycles, that is, the i-th cycle.

The cable structure “initial health state vector d _o ⁱ ” required at the beginning of the i-th cycle (as shown in formula (1)), let d _o ⁱ represent the cable structure at the beginning of the i-th cycle (using the mechanical calculation benchmark model A ⁱ represents the initial health state of the cable structure.

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; oj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula (1), d ⁱ _oj (i=1, 2, 3, ...; j = 1, 2, 3, ..., N) indicates that at the beginning of the i-th cycle, the mechanical calculation benchmark model A The current health status of the jth evaluated object of the cable system in ⁱ , if the evaluated object is a cable (or pull rod) in the cable system, then d _i represents its current damage, and when d _i is 0, it means no Damage, when it is 100%, it means that the cable completely loses its bearing capacity, when it is between 0 and 100%, it means that it loses the corresponding proportion of bearing capacity, if the evaluated object is a displacement component of a support, then d _i represents its The current displacement value. In formula (1), T represents the transposition of the vector (the same below).

When the initial health state vector (denoted as d ¹ _o according to formula (1)) is established at the beginning of the first cycle, the initial health state vector of the evaluated object is established by using the non-destructive testing data of the cable and other data that can express the health state of the cable and the support displacement measurement. Health state vector d ¹ _o . If there is no non-destructive testing data of the cable and other data that can express the healthy state of the cable, or when the initial state of the structure can be considered as a state of no damage and no relaxation, the value of each element related to the cable in the vector d ¹ _o is set to 0.

The initial health state vector d ⁱ _o of the evaluated object required at the beginning of the i-th (i=2, 3, 4, 5, 6...) cycle is in the previous (i-1th, i=2, 3 , 4, 5, 6...) calculated before the end of the cycle, the specific method will be described later.

The mechanical calculation benchmark model that needs to be established at the beginning of the i-th cycle or the established mechanical calculation benchmark model is denoted as A ⁱ .

According to the actual measurement data of the cable structure when the cable structure is completed (including the cable structure shape data, cable force data, pull rod tension data, cable structure support coordinate data, cable structure modal data and other measured data), the cable-stayed bridge and suspension bridge In other words, bridge type data, cable force data, bridge modal data, cable non-destructive testing data and other data that can express the health status of the cable), design drawings, as-built drawings, established by mechanical methods (such as finite element method) A _o ; If there is no actual measurement data of the structure when the cable structure is completed, then the actual measurement of the structure should be carried out before the establishment of the health monitoring system to obtain the actual measurement data of the cable structure (including cable structure shape data, cable force data, tie rod tension data, Cable structure support coordinate data, cable structure modal data and other measured data, for cable-stayed bridges and suspension bridges, bridge type data, cable force data, bridge modal data, cable non-destructive testing data, etc. The health status data), according to this data and the design drawing and as-built drawing of the cable structure, use mechanical methods (such as finite element method) to establish A _o . Regardless of the method used to obtain A _o , the calculated data of the cable structure based on A _o (for cable-stayed bridges and suspension bridges, the bridge type data, cable force data, and bridge modal data) must be very close to the measured data. Data, the error is generally not greater than 5%. In this way, the strain calculation data, cable force calculation data, cable structure shape calculation data, displacement calculation data, cable structure angle data, etc. under the simulated situation obtained by A _o calculation can be reliably close to the measured data when the simulated situation actually occurs . A _o is constant and is only established at the beginning of the first loop.

The basic model for mechanical calculation of the cable structure established at the beginning of the first cycle is denoted as A ¹ , and A ¹ is equal to A _o . The health status of the assessed object corresponding to A ¹ is described by d ¹ _o .

The mechanical calculation benchmark model A ⁱ required at the beginning of the i-th (i=2, 3, 4, 5, 6...) cycle is the previous (i-1th, i=2, 3, 4, 5 , 6...) calculated before the end of the cycle, the specific method will be described later.

After the mechanical calculation benchmark model A ¹ and the initial health state vector d ¹ _o of the evaluated object are available, the health state of each evaluated object in the model A ¹ is expressed by the vector d ¹ _o . On the basis of A ¹ , the health status values of all evaluated objects are changed to 0, and the mechanical model A ¹ is updated to a mechanical model (denoted as A ⁰ ) in which the health status of all evaluated objects is 0. The mechanical model A ⁰ is actually the mechanical model corresponding to the intact cable structure without support displacement. The model A ⁰ may be called the undamaged and unsupported displacement model A ⁰ of the cable structure.

In the present invention, the initial value vector C ⁱ _o "(i=1, 2, 3, ...) of the monitored quantity is used to represent all designated The initial value of the monitored quantity (see formula (2)), the full name of C ⁱ _o is "the initial value vector of the monitored quantity in the i-th cycle".

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ok</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; oM</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In formula (2), C ⁱ _ok (i=1, 2, 3, ...; k = 1, 2, 3, ..., M; M≥N;) is the The kth monitored quantity. The vector C ⁱ _o is formed by arranging the M monitored quantities defined above according to a certain order, and there is no special requirement for the order of arrangement, it is only required that all related vectors also arrange the data in this order.

At the beginning of the first cycle, "the initial value vector C ¹ _o of the monitored quantity in the first cycle" (see formula (2)) is composed of measured data, since the initial value of the monitored quantity calculated according to the model A ¹ is reliably Close to the corresponding actual measured value, in the following description, the same symbol will be used to represent the calculated value component vector and the actual measured value component vector.

The "initial numerical vector C ⁱ _o of the monitored quantity of the i-th cycle" required at the beginning of the i-th (i=2, 3, 4, 5, 6...) cycle is in the previous (i-1th) , i=2, 3, 4, 5, 6...) calculated before the end of the cycle, the specific method will be described later.

Step 2: Each cycle needs to establish the "value change matrix of monitored quantity per unit damage" and "nominal unit damage vector". The "value change matrix of monitored quantity per unit damage" established in the ith cycle is recorded ^as The "nominal unit damage vector" established in the second cycle is denoted as D ⁱ _u , i=1, 2, 3, . . .

The cable structure "value change matrix of monitored quantity per unit damage" established in the first cycle is recorded as ΔC ¹ . The procedure for establishing ΔC ¹ is as follows:

Several calculations are performed on the basis of the mechanical calculation benchmark model ^A1 of the cable structure, and the number of calculations is numerically equal to N. Each calculation assumes that only one evaluated object has unit damage, specifically, if the evaluated object is a supporting cable in the cable system, then it is assumed that the supporting cable has unit damage (for example, 5%, 10%, 20% % or 30% damage as a unit damage), if the evaluated object is a displacement component of a support in one direction, it is assumed that the support has a unit displacement in the displacement direction (for example, 10mm, 20mm, 30mm, etc. are unit displacements ). For the convenience of description, the present invention collectively refers to the assumed damage of the support cable and the displacement of the support as unit damage. For the convenience of calculation, when setting the unit damage in each cycle, the structural health state at the beginning of the cycle can be regarded as completely healthy, and the unit damage is set on this basis (in the subsequent steps, the calculated , The value of the health state of the evaluated object --- called the nominal health state vector d ⁱ _c (i=1, 2, 3, ...), all are relative to the health state of the index structure at the beginning of this cycle It is considered to be completely healthy, so the calculated nominal health status value must be converted into a real health status value according to the formula given later). The evaluated object with unit damage in each calculation of the same cycle is different from the evaluated object with unit damage in other calculations, and the unit damage value of the evaluated object with unit damage can be different from other evaluated objects in each calculation The unit damage value of the object, use the "nominal unit damage vector D ⁱ _u " (as shown in formula (3)) to record the assumed unit damage of all evaluated objects in each cycle, and record it as D ¹ _u in the first cycle . Each calculation uses a mechanical method (such as the finite element method) to calculate the current calculated values of the M monitored quantities specified in the front of the cable structure, and the current calculated values of the M monitored quantities obtained from each calculation form a "being monitored The calculated current value vector of the monitored quantity" (when it is assumed that the j-th assessed object has unit damage, formula (4) can be used to express the calculated current value vector C ¹ _tj of all the specified M monitored quantities); The calculation of the monitored quantity is calculated by subtracting the initial numerical vector C ¹ _o of the monitored quantity from the current numerical vector of the monitored quantity. Vector" (when the jth evaluated object has unit damage, use δC ¹ _j to represent the value change vector of the monitored quantity, the definition of δC ¹ _j is shown in formula (5), formula (6) and formula (7), formula (5) is obtained by subtracting formula (2) from formula (4) and then dividing by the jth element D _uj of vector D ¹ _u ), and each element of the value change vector δC ¹ _j of the monitored quantity represents that due to the calculation It is assumed that the evaluated object with unit damage (such as the jth evaluated object) has unit damage (such as D _uj ), and the value change of the monitored quantity corresponding to the element is relative to the assumed unit damage D _uj rate of change; if there are N evaluated objects, there are N "value change vectors of the monitored quantity", and each numerical change vector of the monitored quantity has M (generally, M≥N) elements. The "value change vector of the monitored quantity" is composed in turn of a "value change matrix ΔC ¹ of the monitored quantity for unit damage" (M rows and N columns) with M×N elements, and each vector δC ¹ _j (j=1, 2, 3, ..., N) is a column of the matrix ΔC ¹ , and the definition of ΔC ¹ is shown in formula (8).

${\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; uj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

The element D ⁱ _uj (i=1, 2, 3, ...; j = 1, 2, 3, ..., N) of the nominal unit damage vector D ⁱ _u in formula (3) represents the ith The unit damage value of the jth evaluated object assumed in the loop, the value of each element in the vector D ⁱ _u can be the same or different.

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tk</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tk</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tjk</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; lm\; w</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In formula (4), element C ⁱ _tjk (i=1,2,3,...; j=1,2,3,...,N; k=1,2,3,... ..., M; M≥N) indicates that when the i-th cycle has unit damage due to the j-th evaluated object, the current value of the k-th specified monitored quantity corresponding to the numbering rule is calculated.

${\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; uj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

The superscript i (i=1,2,3,...) of each amount in the formula (5) represents the i cycle, and the subscript j (j=1,2,3,..., N) indicates that the jth evaluated object has unit damage, where D ⁱ _uj is the jth element in the vector D ⁱ _u . The definition of vector δC ⁱ _j is shown in formula (6), the kth (k=1, 2, 3 _, ..., M; M≥N) element δC ⁱ _jk of δC ⁱ j represents the In the i cycle, when the matrix ΔC ⁱ is established, assuming that the j-th evaluated object has unit damage, the rate of change of the k-th monitored quantity relative to the assumed unit damage D ⁱ _uj is calculated, which is defined as (7) shown.

$\mathrm{<span\; class="notranslate">\; \&delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\text{<span class="notranslate"> i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}\mathrm{<span\; class="notranslate">\; \&delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; \&delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& \mathrm{<span\; class="notranslate">\; \&delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; jk</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; jM</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; jk</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tjk</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ok</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; uj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

The definitions of the quantities in formula (7) have been described above.

${\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; \&delta;\; C</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

In the formula (8), the vector δC ⁱ _j (i=1, 2, 3, ...,, j = 1, 2, 3, ..., N) represents the i-th cycle In , the relative value changes of all monitored quantities due to the unit damage D ⁱ _uj of the jth evaluated object. The numbering rule of the column (subscript j) of the matrix ΔC ⁱ is the same as the numbering rule of the subscript j of the elements of the previous vector d ⁱ _o .

Step 3: Identify the current state of health of the assessed object (identify bearing displacement, damaged and slack cables).

The specific process is as follows.

In the i-th (i=1, 2, 3, ...) cycle, "the current (calculated or measured) numerical vector C ⁱ of the monitored quantity" is the same as "the initial numerical vector C ⁱ _o of the monitored quantity", " The approximate linear relationship between the unit damage monitored quantity numerical change matrix ΔC ⁱ ” and the “current nominal health state vector d ⁱ _c ” is shown in formula (9) or formula (10).

${\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&CenterDot;</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

The definition of the current (calculated or measured) numerical vector C ⁱ of the monitored quantity in formula (9) and formula (10) is similar to the definition of the initial numerical vector C ⁱ _o of the monitored quantity, see formula (11); the evaluated object The definition of the current nominal health state vector d ⁱ _c is shown in formula (12).

${\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 11</span>}<span\; class="notranslate">\; )</span>$

The element C ⁱ _k (i=1, 2, 3, ...; k = 1, 2, 3, ..., M; M≥N) in formula (11) is the first The current value of the monitored quantity with the number k corresponding to the index structure according to the numbering rules at the time of the i cycle.

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; cj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; n</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 12</span>}<span\; class="notranslate">\; )</span>$

In formula (12), d ⁱ _cj (i=1, 2, 3, ...; j = 1, 2, 3, ..., N) is the cable structure in the i-th cycle The current nominal damage value of the jth evaluated object, the numbering rule of the subscript j of the element of the vector d ⁱ _c is the same as the numbering rule of the column of the matrix ΔC ⁱ .

When the actual damage of the evaluated object or the displacement of the support is not too large, since the cable structure material is still in the linear elastic stage, the deformation of the cable structure is also small, such a linear relationship represented by formula (9) or formula (10) The error with the actual situation is small, and the error can be defined by the error vector e ⁱ (Equation (13)), which represents the error of the linear relationship shown in Equation (9) or Equation (10).

${\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; abs</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 13</span>}<span\; class="notranslate">\; )</span>$

Ads() in formula (13) is an absolute value function, and the absolute value is taken for each element of the vector obtained in the brackets.

Since there is a certain error in the linear relationship represented by formula (9) or formula (10), it cannot be solved directly according to formula (9) or formula (10) and "the current (measured) value vector C ⁱ of the monitored quantity". Get the current nominal health state vector d ⁱ _c . And obtaining an acceptable solution of the current nominal health state vector d ⁱ _c (that is, with reasonable error, but can accurately determine the position of the damaged cable and its damage degree, and determine the displacement of the support from the cable system) becomes a Reasonable solution, available formula (14) to express this method.

$\mathrm{<span\; class="notranslate">\; abs</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 14</span>}<span\; class="notranslate">\; )</span>$

In Equation (14), abs() is an absolute value function, and the vector g ⁱ describes the reasonable deviation from the ideal linear relationship (Equation (9) or Equation (10)), which is defined by Equation (15).

${\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; g</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 15</span>}<span\; class="notranslate">\; )</span>$

In formula (15), g ⁱ _k (i=1, 2, 3, ....; k = 1, 2, 3, ..., M) describes the i-th cycle The maximum allowable deviation from the ideal linear relationship shown in formula (9) or formula (10). The vector g ⁱ can be selected according to the error vector e ⁱ defined by formula (13).

When the initial numerical vector C ⁱ _o of the monitored quantity (obtained by actual measurement or calculation), the numerical change matrix ΔC ⁱ (obtained by calculation) of the monitored quantity per unit damage and the current numerical vector C ⁱ (obtained by actual measurement) of the monitored quantity are known, Equation (14) can be solved using a suitable algorithm (such as a multi-objective optimization algorithm) to obtain an acceptable solution to the current nominal health state vector d ⁱ _c , and the elements of the current actual health state vector d ⁱ (see equation (16) for definition) It can be calculated according to formula (17), that is, the current actual health state vector d ⁱ of the evaluated object is obtained, so that the position and damage degree of the damaged cable can be determined by d ⁱ , and the displacement of the support can be determined, that is, the damage identification is realized and support displacement identification.

${\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span>$

In formula (16), d ⁱ _j (i=1, 2, 3, ...; j = 1, 2, 3, ..., N) represents the value of the jth evaluated object in the ith cycle Actual damage value, its definition is shown in formula (17). If the evaluated object is a cable (or tie rod) in the cable system, then d ⁱ _j represents its current damage, and when d ⁱ _j is 0, it means that the cable has no damage , when it is 100%, it means that the cable has completely lost its bearing capacity, and when it is between 0 and 100%, it means that the cable has lost its corresponding proportion of bearing capacity. It is found that the cable is not damaged, then d _i represents the mechanical equivalent relaxation of the cable and the damage value of d ⁱ , thus the slack cable is determined, and the calculation method of the specific slack amount is explained below; A displacement component of the seat, then d ⁱ _j represents its current displacement value. The numbering rule of the elements of the vector d ⁱ is the same as the numbering rule of the elements of the vector d ⁱ ₀ in formula (1).

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; oj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; cj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 17</span>}<span\; class="notranslate">\; )</span>$

In formula (17), d ⁱ _oj (i=1, 2, 3, 4, ...; j = 1, 2, 3, ..., N) is the jth element of vector d ⁱ _o , d ⁱ _cj is the jth element of the vector d ⁱ _c .

The following describes how to determine the position and degree of relaxation of the slack cable after the current actual health state vector d of the cable structure is obtained.

It is known that there are Q supporting cables in the cable system, and the structural supporting cable force data is described by the cable forces of Q supporting cables. The "initial cable force vector F _o " can be used to represent the initial cable force of all supporting cables in the cable structure (see formula (18) for definition). Because the initial cable force calculated based on the calculation benchmark model of the cable structure is reliably close to the measured data of the initial cable force, in the following description, the calculated value and the measured value will be represented by the same symbol.

F _o ＝[F _o1 F _o2 ...F _ok ...F _oQ ] ^T (18)

In formula (18), F _o (k=1, 2, 3, ..., Q) is the initial cable force of the kth supporting cable in the cable structure, and this element corresponds to the specified supporting cable according to the numbering rules cable force. Vector F _o is constant. The vector F _o is used when establishing the benchmark model A _o for the initial mechanical calculation of the cable structure.

In the present invention, "current cable force vector F ⁱ " is used to represent the current cable force of all supporting cables in the cable structure measured at the i-th cycle (see formula (19) for definition).

${\mathrm{<span\; class="notranslate">\; f</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; Q</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 19</span>}<span\; class="notranslate">\; )</span>$

In formula (19), F ⁱ _k (i=1, 2, 3, 4, ...; k = 1, 2, 3, ..., Q) is the kth The current cable force of the root support cable.

In the present invention, under the initial state of the support cable (no damage, no slack), and the support cable is in a free state (free state means that the cable force is 0, the same hereinafter), the length of the support cable is called the initial free length, and is expressed by " The initial free length vector l _o ” represents the initial free length of all supporting cables in the cable structure (see formula (20) for definition).

l _o ＝[l _o1 l _o2 ...l _ok ...l _oQ ] ^T (20)

In formula (20), l _ok (k=1, 2, 3, . . . , Q) is the initial free length of the kth supporting cable in the cable structure. The vector l _o is a constant, which has nothing to do with the number of cycles, and will not change after it is determined at the beginning of the first cycle.

In the present invention, "current free length vector l ⁱ " is used to represent the current free lengths of all supporting cables in the cable structure at the i-th cycle (see formula (21) for definition).

${\mathrm{<span\; class="notranslate">\; l</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; Q</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; one</span>}<span\; class="notranslate">\; )</span>$

In the formula (21), l ⁱ _k (i=1, 2, 3, 4, ...; k = 1, 2, 3, ..., Q) is the kth The current free length of the root support cable.

In the present invention, the "free length change vector Δl ⁱ " (or the current slackness vector of the support cables) is used to represent the changes in the free lengths of all the support cables in the cable structure during the ith cycle (see formula (22) and formula (twenty three)).

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; Q</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}<span\; class="notranslate">\; )</span>$

In formula (22), Δl ⁱ _k (i=1, 2, 3, 4, ...; k = 1, 2, 3, ..., Q) is the current (i-th cycle) cable structure The change of the free length of the k-th supporting cable is defined in formula (23). The cable whose ^Δli _k is not 0 is the slack cable, and the value of ^Δli _k is the slack amount of the cable, and represents the The current slack degree of the root support cable is also the cable length adjustment amount of the cable when the cable force is adjusted.

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; ok</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}<span\; class="notranslate">\; )</span>$

In the present invention, the slack degree identification of the slack cable is carried out by performing mechanical equivalent of the slack cable with the damaged cable, and the equivalent mechanical condition is:

1. The initial free length, geometric characteristic parameters and material mechanical characteristic parameters of the two equivalent cables are the same when there is no relaxation and no damage;

2. After relaxation or damage, the cable force and the total length after deformation of the two equivalent slack cables and damaged cables are the same.

When the above two equivalent conditions are satisfied, the mechanical functions of such two supporting cables in the structure are exactly the same, that is, if the equivalent damaged cable is used to replace the slack cable, the cable structure will not change, and vice versa. Of course.

In the present invention, during the ith cycle, if the current actual virtual damage degree of the virtual damaged support cable equivalent to the k-th support cable (its current degree of relaxation is defined by Δl ⁱ _k ) is represented by d ⁱ _j ( For the definition of d ⁱ _j see formula (16) and formula (17)). The relationship between the current slack degree Δl ⁱ _k (the definition of Δl ⁱ _k is shown in Equation (22)) of the relaxed k-th supporting cable and the current actual virtual damage degree d ⁱ _j of the equivalent damaged cable is determined by the above two mechanics Equivalent conditions are determined. The specific relationship between Δl ⁱ _k and d ⁱ _j can be realized by various methods, for example, it can be determined directly according to the aforementioned equivalent conditions (see formula (24)), or it can be replaced by the equivalent elastic modulus based on Ernst (24 ) in E after correction (see formula (25)), it can also be determined by other methods such as trial algorithm based on finite element method.

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; EA</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; ok</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; four</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; E.</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\frac{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; AE</span>}}{\mathrm{<span\; class="notranslate">\; 12</span>}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}}}<span\; class="notranslate">\; ]</span>\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; ok</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 25</span>}<span\; class="notranslate">\; )</span>$

In formula (24) and formula (25), E is the elastic modulus of the supporting cable, A is the cross-sectional area of the supporting cable, F ⁱ _j is the current cable force of the supporting cable, and d ⁱ _j is the The current actual virtual damage degree, ω _k is the weight per unit length of the supporting cable, and l ⁱ _kx is the horizontal distance between the two supporting ends of the supporting cable. The term in [] in Equation (25) is the Ernst equivalent elastic modulus of the supporting cable, and the current slackness vector Δl ⁱ of the supporting cable can be determined from Equation (24) or Equation (25). Equation (25) is a modification of Equation (24).

The fourth step: judge whether to end this (i-th) cycle, if yes, then complete the finishing work before the end of this cycle, for the next time (i.e. i+1 time, i=1, 2, 3, 4 , ...) loop to prepare the benchmark model and necessary vectors for mechanics calculations. The specific process is as follows.

After obtaining the current nominal health state vector d ⁱ _c in this (i-th) cycle, first, establish the identification vector B ⁱ according to formula (26), and formula (27 ⁾ gives the jth The definition of elements; if the elements of the identification vector B ⁱ are all 0, then continue to monitor and calculate the health of the cable structure in this cycle; if the elements of the identification vector B ⁱ are not all 0, after completing the subsequent steps, enter the next step one cycle. The so-called follow-up steps are: first, calculate the initial damage vector d ⁱ⁺¹ _o required for the next (i+1th, i=1, 2, 3, 4, ...) cycle according to formula (28) Each element d ⁱ⁺¹ _oj ; secondly, on the basis of mechanical calculation benchmark model A ⁱ (i=1, 2, 3, 4,…) or cable structure damage-free model A ⁰ , let the evaluated object After the health status is d ⁱ⁺¹ _o , the mechanical calculation benchmark model A ⁱ⁺¹ required for the next (i+1th, i=1, 2, 3, 4, ...) cycle is obtained; finally, by The calculation of the mechanical calculation benchmark model A ⁱ⁺¹ obtains the initial value of the monitored quantity, which constitutes the "monitored The initial numerical vector C ⁱ⁺¹ _o "(i=1, 2, 3, 4, . . . ) of the quantity.

${\mathrm{<span\; class="notranslate">\; B</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 26</span>}<span\; class="notranslate">\; )</span>$

The superscript i of the identification vector B ⁱ in formula (26) represents the i-th cycle, and the subscript j of its element B ⁱ _j (j=1, 2, 3, ..., N) represents the damage of the j-th evaluated object The characteristic can only take two quantities of 0 and 1, and the specific value rules are shown in formula (27).

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>& \mathrm{<span\; class="notranslate">\; if</span>}& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; cj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; uj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\\ \mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>& \mathrm{<span\; class="notranslate">\; if</span>}& {\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; cj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; uj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 27</span>}<span\; class="notranslate">\; )</span>$

In formula (27), the element B ⁱ _j is the jth element of the identification vector B ⁱ , D ⁱ _uj is the jth element of the nominal unit damage vector D ⁱ _u (see formula (3)), d ⁱ _cj is the current nominal The jth element of the health state vector d ⁱ _c (see formula (12)), they all represent the relevant information of the jth evaluated object.

${\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; oj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; oj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; uj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 28</span>}<span\; class="notranslate">\; )</span>$

In formula (28), D ⁱ _uj is the jth element of the nominal unit damage vector D ⁱ _u (see formula (3)), and d ⁱ _cj is the jth element of the current nominal health state vector d ⁱ _c (see formula ( 12)).

The second part of the present invention: the software and hardware parts of the health monitoring system.

The hardware part includes the monitored quantity monitoring system, signal collector and computer. Real-time or quasi-real-time monitoring of each monitored quantity is required.

The software should have the following functions: the software part should be able to complete the process set in the first part of the present invention, that is, complete the monitoring, recording, control, storage, calculation, notification, and alarm that are required in the present invention and can be realized by computers. and other functions.

The inventive method specifically comprises:

a. For the convenience of description, the present invention collectively refers to the evaluated support cables and bearing displacement components as the evaluated object, and the sum of the number of the evaluated support cables and the support displacement components is N, that is, the evaluated object The quantity is N; Determine the numbering rule of the evaluated object, according to this rule, all the evaluated objects in the index structure will be numbered, and this numbering will be used to generate vectors and matrices in subsequent steps; the present invention uses variable j to represent this numbering , j=1, 2, 3, ..., N;

b. Assuming that there are Q supporting cables in the cable system, the structural cable force data includes the cable forces of these Q supporting cables. Obviously, Q is smaller than the number N of the evaluated objects; only the Q cable force data of Q supporting cables can be used to solve the problem It is impossible to know the status of N evaluated objects. On the basis of monitoring the force of all Q supporting cables, the present invention artificially adds M ₂ cables in the structure, and will monitor the newly added cables during the structural health monitoring process. The cable force of M ₂ cables; based on the above-mentioned monitored quantities, there are M cable forces of M cables to be monitored in the whole structure, that is, there are M monitored quantities, where M is the sum of Q and M ₂ ; M must not be less than the measured The number of evaluation objects N; the stiffness of the newly added M ₂ cables should be much smaller than the stiffness of any supporting cable in the cable structure; the cable force of the newly added M ₂ cables should be much smaller than that of any supporting cable in the cable structure The cable force of the root supporting cable is much smaller, which can ensure that even if the newly added _M2 cables are damaged or slack, the influence on the stress, strain and deformation of other components of the cable structure is minimal; the newly added _M2 cables The normal stress on the cross-section of , should be less than its fatigue limit, these requirements can ensure that the newly added M ₂ cables will not suffer from fatigue damage; the two ends of the newly added M ₂ cables should be fully anchored to ensure that there will be no slack; the new The increased _M2 cables should be fully protected against corrosion to ensure that the newly added _M2 cables will not be damaged or loosened; Monitored quantity"; serial numbers are given to M monitored quantities, which will be used to generate vectors and matrices in subsequent steps;

c. Use the nondestructive testing data of the assessed object and other data that can express the health status of the assessed object to establish the initial health state vector d ⁱ _o of the assessed object; if there is no nondestructive testing data of the assessed object, each vector d ⁱ _o The element value is 0; the numbering rule of the element of the vector d ⁱ _o is the same as the numbering rule of the evaluated object; the present invention represents the number of cycles with i, i=1, 2, 3,...; here is the first In the second cycle, i takes 1, that is, the initial health state vector d ⁱ _o established here can be embodied as d ¹ _o ;

d. While establishing the initial health state vector d ¹ _o , directly measure and calculate the initial values of all the monitored quantities of the cable structure, and form the initial value vector C ⁱ _o of the monitored quantities; here is the first cycle, i takes 1, that is, the initial numerical vector C ⁱ _o of the monitored quantity established here can be embodied as C ¹ _o ; while the initial numerical vector C ¹ _o of the monitored quantity is obtained from the actual measurement, the initial geometric data and initial index of the cable structure are obtained from the actual measurement. Structural support coordinate data; the initial cable force of all supporting cables is obtained by direct measurement and calculation, which forms the initial cable force vector F _o ; at the same time, the initial free length of all supporting cables is obtained according to the structural design data and completion data, and forms the initial free length vector l _o ; the vector F _o and the vector l _o are constant; at the same time, the elastic modulus, density, and initial cross-sectional area of all cables are obtained from actual measurements or according to structural design and completion data;

e. Establish the mechanical calculation reference model A ⁱ of the cable structure according to the design drawing, as-built drawing and the measured data of the cable structure, the non-destructive testing data of the cable and the initial coordinate data of the support of the cable structure; here is the first cycle, i Take 1, that is, the mechanical calculation benchmark model A ⁱ of the cable structure established here can be embodied as A ¹ ;

f. Carry out several mechanical calculations on the basis of the mechanical calculation benchmark model A ⁱ , and obtain the "unit damage monitored quantity numerical change matrix ΔC ⁱ " and "nominal unit damage vector D ⁱ _u ";

g. The current measured values of all the specified monitored quantities of the cable structure obtained from the actual measurement form the "current value vector C ⁱ of the monitored quantity"; when numbering the elements of all vectors that appear in this step and before this step, the same number should be used In this way, it can be guaranteed that the elements with the same number in each vector appearing in this step and before this step represent the same monitored quantity and correspond to the relevant information defined by the vector to which the element belongs; The current cable force constitutes the current cable force vector F ⁱ ; the spatial coordinates of the two supporting end points of all supporting cables are obtained through actual measurement and calculation, and the difference in the horizontal component of the spatial coordinates of the two supporting end points is the horizontal distance between the two supporting end points;

h. In the process of structural health monitoring, conduct non-destructive testing on the newly added M ₂ cables, and identify damaged or loose cables;

i. According to the numbering rules of the monitored quantities, remove the elements corresponding to the damaged or loose cables identified in step h from the initial value vector C ⁱ _o of the monitored quantities; Remove the row corresponding to the damaged or slack cable identified in step h in the quantitative value change matrix ΔC ⁱ ;

j. Define the current nominal health state vector d ⁱ _c and the current actual health state vector d ⁱ , the number of elements of the two damage vectors is equal to the number of evaluated objects, and the element value of the current nominal health state vector d ⁱ _c represents the corresponding evaluated The current nominal damage degree or support displacement of the object, the element value of the current actual health state vector d ⁱ represents the current actual damage degree or support displacement of the corresponding evaluated object, and the number of elements of the two damage vectors is equal to the evaluated object There is a one-to-one correspondence between the elements of the two damage vectors and the evaluated object, and the numbering rules of the elements of the two damage vectors are the same as the numbering rules of the evaluated object;

k. Based on the "current numerical vector C ⁱ of the monitored quantity" and "the initial numerical vector C ⁱ _o of the monitored quantity", "the numerical change matrix of the monitored quantity per unit damage ΔC ⁱ " and "the current nominal health state vector d ⁱ _c The approximate linear relationship between ” can be expressed as formula 1. In formula 1, other quantities except d ⁱ _c are known, and the current nominal health state vector d ⁱ _c can be calculated by solving formula 1;

$C^i=C_o^i+\mathrm{\&Delta;}{C}^i\&CenterDot;d_c^i$ Formula 1

l. Using the relationship between the current actual health state vector d ⁱ expressed in formula 2 and the initial damage vector d ⁱ _o and the current nominal health state vector d ⁱ _c , calculate all the elements of the current actual health state vector d ⁱ ;

$d_j^i=1-(1-d_{\mathrm{oj}}^i)(1-d_{\mathrm{cj}}^i)$ Formula 2

In formula 2, j=1, 2, 3,..., N;

The element values of the current actual health state vector d ⁱ represent the actual damage degree or the actual support displacement of the corresponding evaluated object. According to the current actual health state vector d ⁱ , it can be determined which cables are damaged and the damage degree, and the actual Support displacement; if an element of the current actual health state vector corresponds to a cable in the cable system, and its value is 0, it means that the cable corresponding to the element is intact without damage or slack. If the value is 100%, it means that the cable corresponding to this element has completely lost its carrying capacity; if its value is between 0 and 100%, it means that the cable has lost the corresponding proportion of carrying capacity; if the current actual health state vector A certain element corresponds to a displacement component of a support, then d ⁱ _j represents its current displacement value;

m. Identify damaged cables from the problematic support cables identified in step 1, leaving slack cables remaining.

n. Use the current actual virtual damage vector d ⁱ obtained in step 1 to obtain the current actual virtual damage degree of the slack cable, use the current cable force vector F ⁱ obtained in step g, and use all the supporting cables obtained in step g The horizontal distance between the two supporting end points of , using the initial free length vector l _o obtained in step d, using the elastic modulus, density, and initial cross-sectional area data of all cables obtained in step d, by combining the slack cables with The mechanical equivalent of the damaged cable is used to calculate the relaxation degree of the slack cable, which is equivalent to the current actual virtual damage degree. The equivalent mechanical condition is: the initial free length of the two equivalent cables without relaxation and without damage 1. Geometric characteristic parameters, density and mechanical characteristic parameters of the material are the same; 2. After relaxation or damage, the cable force and the total length after deformation of the two equivalent relaxed cables and damaged cables are the same; when the above two equivalent conditions are satisfied, such The mechanical functions of the two supporting cables in the structure are exactly the same, that is, if the damaged cable is replaced by an equivalent slack cable, the cable structure will not change, and vice versa; according to the aforementioned mechanical equivalent conditions, the The degree of slack of those judged as slack cables, the degree of slack is the amount of change in the free length of the support cables, that is, the cable length adjustment of those support cables whose force needs to be adjusted is determined; in this way, the slack identification of the support cables is realized; calculation The required cable force is given by the corresponding element of the current cable force vector Fi.

o. After obtaining the current nominal health state vector d ⁱ _c , establish the identification vector B ⁱ according to formula 3, and formula 4 gives the definition of the jth element of the identification vector B ⁱ ;

$B^i={\left[\begin{array}{cccccccccc}{B}_1^i& B_2^i& .& .& .& B_j^i& .& .& .& B_N^i\end{array}\right]}^T$ Formula 3

$B_j^i=\left\{\begin{array}{ccc}0,& \mathrm{if}& d_{\mathrm{cj}}^i<{\mathrm{D.}}_{\mathrm{uj}}^i\\ 1,& \mathrm{if}& d_{\mathrm{cj}}^i\&Greater\; Equal;{\mathrm{D.}}_{\mathrm{uj}}^i\end{array}\right.$ Formula 4

In formula 4, the element B ⁱ _j is the jth element of the identification vector B ⁱ , D ⁱ _uj is the jth element of the nominal unit damage vector D ⁱ _u , d ⁱ _cj is the jth element of the current nominal health state vector d ⁱ _c elements, they all represent the relevant information of the jth evaluated object, j=1, 2, 3, ..., N in formula 4;

p. If the elements of the identification vector B ⁱ are all 0, then return to the gth step to continue this cycle; if the elements of the identification vector F ⁱ are not all 0, then enter the next step, the qth step;

q. Calculate each element d i+1 _oj of the initial damage vector d ⁱ⁺¹ _o required for the next cycle, that is, the ^i+1th cycle, according to formula 5;

$d_{\mathrm{oj}}^{i+1}=1-(1-d_{\mathrm{oj}}^i)(1-{\mathrm{D.}}_{\mathrm{uj}}^i{f}_j^i)$ Formula 5

In formula 5, D ⁱ _uj is the jth element of the nominal unit damage vector D ⁱ _u , d ⁱ _cj is the jth element of the current nominal health state vector d ⁱ _c , and F ⁱ _j is the jth element of the identity vector F ⁱ Elements, j=1, 2, 3, ..., N in formula 5; the numbering rule of the elements of the vector d ⁱ⁺¹ _o is the same as the numbering rule of the evaluated object;

r. On the basis of the mechanical calculation benchmark model A ⁱ , let the health status of the evaluated object be d ⁱ⁺¹ _o and then update to obtain the next mechanical calculation benchmark model A i+ ¹ required for the i+1th cycle ;

s. Through the calculation of the mechanical calculation benchmark model A ^i+1, the strain values corresponding to all monitored strain points of the structure of the model A ⁱ⁺¹ and the strain directions to be monitored are obtained, and these values form the next time, that is, The initial numerical vector C ⁱ⁺¹ _o of the monitored quantity required for the i+1th cycle;

t. Go back to step f and start the next cycle.

In step f, several mechanical calculations are carried out on the basis of the mechanical calculation benchmark model A ⁱ , and the specific method to obtain the "unit damage monitored quantity numerical change matrix ΔC ⁱ " and "nominal unit damage vector D ⁱ _u " is as follows: :

f1. Carry out several mechanical calculations on the basis of the mechanical calculation benchmark model A ⁱ of the cable structure, and the number of calculations is numerically equal to N; perform calculations in sequence according to the numbering rules of the evaluated objects; each calculation assumes that only one evaluated object is in the original Add unit damage or unit displacement on the basis of damage or displacement. Specifically, if the evaluated object is a supporting cable in the cable system, then it is assumed that the supporting cable adds unit damage. If the evaluated object is For the displacement component of a support in one direction, it is assumed that the support increases unit displacement in the direction of displacement, and the evaluated object that increases unit damage or unit displacement in each calculation is different from that in other calculations that increases unit damage or For the evaluated object of the unit displacement, use the “nominal unit damage vector D ⁱ _u ” to record all assumed additional unit damage or unit displacement, where i represents the i-th cycle, and each calculation uses the mechanical method to calculate the The current calculated values of all the monitored quantities, the current calculated values of all the monitored quantities obtained by each calculation form a monitored quantity to calculate the current value vector;

f2. The current value vector of the monitored quantity calculated by each calculation minus the initial value vector of the monitored quantity is divided by the assumed unit damage or unit displacement value of the calculation to obtain a monitored quantity change vector, and there are N The evaluated object has N monitored quantity change vectors;

f3. From the N monitored quantity change vectors according to the numbering rules of the N evaluated objects, a cable-structured monitored quantity unit change matrix ΔC ⁱ with N columns is sequentially formed.

Beneficial effects: the method disclosed in the invention can monitor and evaluate the health state of the cable structure very accurately (including all support displacements, the positions of all loose and damaged cables, and the degree of slack or damage thereof). Systems and methods are highly beneficial to the safety of cable structures.

Detailed ways

Aiming at the health monitoring of the cable structure, the present invention discloses a system and method capable of reasonably and effectively monitoring the health status of each cable and the displacement component of each support in the cable system in the cable structure at the same time. The following descriptions of embodiments of the invention are merely exemplary in nature, and are in no way intended to limit the application or uses of the invention.

In the case of displacement of the support of the cable structure, occurrence of damaged cables, slack cables, the present invention uses an algorithm for monitoring the health status of the cable structure (including identification of support displacement, damaged cables, slack cables) . During specific implementation, the following steps are one of various steps that may be taken.

The first step: for the convenience of description, the present invention collectively refers to the evaluated support cable and the support displacement component as the evaluated object, and the sum of the quantity of the evaluated support cable and the support displacement component is N, that is, the evaluated The quantity of evaluation object is N; Determine the numbering rule of evaluated object, according to this rule, all evaluated objects in the index structure will be numbered, and this numbering will be used for generating vector and matrix in subsequent steps; The present invention represents this with variable j One number, j=1, 2, 3, ..., N.

Assuming that there are Q supporting cables in the cable system, the structural cable force data includes the cable force of these Q supporting cables, obviously Q is smaller than the number N of the evaluated objects. It is impossible to solve the unknown state of N evaluated objects only by Q cable force data of Q support cables. The present invention increases the number of not less than (N-Q) on the basis of monitoring all Q support cable forces. other monitored quantities.

The other monitored quantities that have been increased by no less than (N-Q) are still cable forces, described as follows:

Artificially increase M ₂ (M ₂ is not less than NQ) cables in the structure, and the stiffness of the newly added M ₂ cables can be much smaller than the tensile stiffness of any supporting cable in the cable structure, for example, 10 times smaller ; The cable force of the newly added M ₂ cables should be much smaller than that of any supporting cable of the cable structure, so as to ensure that even if the newly added M ₂ cables are damaged or slack, the other components of the cable structure The influence of the stress, strain and deformation of the newly added M 2 cables is negligible; the normal stress on the cross-section of the newly added M ₂ cables should be less than its fatigue limit, for example, only half of the fatigue limit, these requirements can ensure that the newly added M ₂ cables Fatigue damage will not occur; both ends of the newly added M ₂ cables shall be fully anchored to ensure that there will be no slack; the newly added M ₂ cables shall be fully protected against corrosion to ensure that the newly added M ₂ cables do not Damage and relaxation will occur; it is also possible to use more cables to ensure the reliability of health monitoring, for example, make M ₂ not less than 2 times NQ, and only select the cable force data of intact cables in the process of structural health monitoring (referred to as the actual monitored quantity that can be used, record its quantity as K, and K must not be less than N) and the corresponding cable structure monitored quantity unit change matrix ΔC for health status assessment. Since M ₂ is not less than 2 times of NQ, it can be Guaranteed to be practical; the cable force of this newly added _M2 cable will be monitored during the structural health monitoring process. The newly added M ₂ cables should be installed on the structure where personnel can easily reach, so that personnel can conduct non-destructive testing on it.

Based on the above-mentioned monitored quantities, the entire structure has M monitored quantities with M (M=Q+M ₂ ) roots, and M must not be less than the number N of evaluated objects. Number the M monitored quantities consecutively, and this number will be used to generate vectors and matrices in subsequent steps.

For the sake of convenience, in the present invention, "all monitored parameters of the structure" are simply referred to as "monitored quantities".

Step 2: Establish the initial health state vector d ¹ _o of the evaluated object by using the non-destructive testing data of the evaluated object and other data that can express the health status of the evaluated object; if there is no non-destructive testing data of the evaluated object, the vector d ¹ _o The value of each element of is 0; the numbering rule of the elements of the vector d ¹ _o is the same as the numbering rule of the evaluated object.

Step 3: At the same time as the initial health state vector d ¹ _o , directly measure and calculate the initial values of all monitored quantities of the cable structure, and form the initial value vector C ¹ _o of the monitored quantities.

Step 4: While obtaining the initial numerical vector C ¹ _o of the monitored quantity, mature measurement methods can be used for cable force measurement, strain measurement, angle measurement and space coordinate measurement. At the same time, the initial cable forces of all the supporting cables of the cable structure are directly measured and calculated to form the "initial cable force vector F _o ". At the same time, the initial free lengths of all cables are obtained according to the structural design data and as-built data, and form the "initial free length vector l _o ". At the same time, the elastic modulus, density, and initial cross-sectional area of all cables are obtained from actual measurements or based on structural design and completion data. At the same time, the initial geometry data of the cable structure (for cable-stayed bridges is the initial bridge type data) can be obtained by direct measurement or calculation after measurement. The initial geometry data of the cable structure can be the spatial coordinate data of all the end points of the cables plus a The spatial coordinate data of a series of points, the purpose is to determine the geometric characteristics of the cable structure according to these coordinate data. For cable-stayed bridges, the initial geometric shape data can be the spatial coordinate data of all cable end points plus the spatial coordinate data of several points on both ends of the bridge, which is the so-called bridge type data.

According to the cable structure design drawing, as-built drawing and the measured data of the cable structure (including the initial geometry data, strain data, initial cable force of all cables, structural modal data and other data), it is a bridge for cable-stayed bridges and suspension bridges. The bridge type data, strain data, cable force data, bridge modal data), cable non-destructive testing data and initial cable structure support coordinate data establish the mechanical calculation benchmark model A _o of the cable structure, based on the mechanical calculation benchmark model A _o The calculated data of the calculated structure must be very close to the measured data, and the error is generally not greater than 5%.

A _o is invariable and is only established at the beginning of the first cycle; the mechanical calculation benchmark model of the cable structure established at the beginning of the i-th cycle is denoted as A ⁱ , where i represents the number of cycles; the letter in the application of the present invention In addition to the place where i clearly represents the step number, the letter i only represents the number of cycles, i.e. the i-th cycle; therefore, the mechanical calculation benchmark model of the cable structure established at the beginning of the first cycle is denoted as A ¹ , and in the present invention, A ¹ is equal to A _o ;

Step 5: Install the hardware part of the cable structure health monitoring system. The hardware part includes at least: cable force monitoring system (for example, including acceleration sensor, signal conditioner, etc.), signal (data) collector, computer and communication alarm equipment. Every monitored quantity must be monitored by the monitoring system, and the monitoring system transmits the monitored signal to the signal (data) collector; the signal is transmitted to the computer through the signal collector; the computer is responsible for running the health monitoring of the cable system of the cable structure The software includes recording the signal transmitted by the signal collector; when the health status of the evaluated object is monitored, the computer controls the communication alarm device to alarm the monitoring personnel, the owner and (or) the designated personnel.

Step 6: Compile and install the health monitoring system software of the cable structure on the monitoring computer. The software is run on every cycle, or the software is always running. This software will complete functions such as monitoring, recording, control, storage, calculation, notification, and alarm required by each task of the present invention (that is, all the work that can be completed with a computer in this specific implementation method), and can be performed regularly or by personnel. The operation health monitoring system generates cable structure health status reports, and can also automatically notify or prompt the monitoring personnel to notify specific technical personnel to complete the necessary calculation work according to the set conditions (such as damage reaching a certain value).

Step 7: Start the cyclic operation from this step, which is recorded as the i-th cycle for convenience of description, wherein i=1, 2, 3, 4, 5, . . .

Step 8: Carry out several mechanical calculations on the basis of the mechanical calculation benchmark model of the cable structure denoted as A ⁱ , and obtain the change matrix ΔC ⁱ of the monitored quantity of damage per unit of the cable structure and the nominal unit damage vector D ⁱ _u through calculation. The specific method is:

a. At the beginning of the i-th cycle, several mechanical calculations are performed on the basis of the mechanical calculation benchmark model A ⁱ of the cable structure, and the number of calculations is numerically equal to N; the calculations are performed sequentially according to the numbering rules of the evaluated objects; each time The calculation assumes that only one assessed object has unit damage or unit displacement on the basis of the original damage or displacement. Specifically, if the assessed object is a support cable in the cable system, then it is assumed that the support cable increases Unit damage, if the evaluated object is the displacement component of a support in one direction, it is assumed that the support will increase the unit displacement in the displacement direction, and the evaluated object with increased unit damage or unit displacement in each calculation is different from For the evaluated object with additional unit damage or unit displacement in other calculations, use the “nominal unit damage vector D ⁱ _u ” to record and record all assumed additional unit damage or unit displacement, where i represents the i-th cycle, and each time All the calculations use the mechanical method to calculate the current calculated values of all the monitored quantities of the cable structure, and the current calculated values of all the monitored quantities obtained by each calculation form a monitored quantity to calculate the current value vector; in this step, the elements of each vector are given When numbering, the same numbering rule should be used with other vectors in the present invention, so that any element in each vector in this step can be guaranteed to express the same monitored quantity or the same evaluated element with the same numbered element in other vectors. Object Information about the object.

b. Subtract the initial value vector of the monitored quantity from the current value vector of the monitored quantity obtained by each calculation, and then divide it by the assumed unit damage or unit displacement value of the calculation to obtain a monitored quantity change vector δC ⁱ _j ; If there are N evaluated objects, there are N monitored variable change vectors δC ⁱ _j (j=1, 2, 3, . . . , N).

c. According to the numbering rules of the N evaluated objects, the N monitored quantity change vectors form a cable structure unit change matrix ΔC ⁱ _o with N columns in turn, and the "unit damage monitored quantity change matrix ΔC ⁱ " The numbering rules of the columns are the same as the element numbering rules of the current nominal health state vector d ⁱ _c and the current actual health state vector d ⁱ defined later.

When numbering the elements of each vector in this step and thereafter, the same numbering rule should be used with other vectors in the present invention, so that it can be guaranteed that any element in each vector in this step is the same as that in other vectors and numbered Elements express the related information of the same monitored quantity or the same object.

Step 9: Establish linear relationship error vector e ⁱ and vector g ⁱ . Using the previous data ("initial value vector C ⁱ _o of the monitored quantity", "change matrix ΔC ⁱ of the monitored quantity per unit damage"), while performing each calculation in the eighth step, that is, in each calculation, it is assumed that the index There is only one evaluated object in the system, and the unit damage or unit displacement is added on the basis of the original damage or displacement. At the same time, each calculation forms a health state vector d ⁱ _t , and the number of elements in the health state vector d ⁱ _t is equal to the The number of evaluation objects, the value of only one element among all the elements of the vector d ⁱ _t is the unit damage value or the increased unit displacement value of the cable that is assumed to increase the unit damage in each calculation, and the value of the other elements of d ⁱ _t is 0 , the number of the element that is not 0 is the same as the corresponding relationship between the evaluated object that is assumed to increase unit damage or unit displacement, and the corresponding relationship between the elements with the same number in other vectors and the index; C ⁱ _tj , C ⁱ _o , ΔC ⁱ , d ⁱ _t are brought into formula (13), and d ⁱ _c of formula (13) is brought in with d ^it _t to obtain a linear relationship error vector e ⁱ , and each calculation obtains a linear relationship error vector e ⁱ ; If there are N evaluated objects, there will be N calculations, and there will be N linear relationship error vectors e ⁱ , and the N linear relationship error vectors e ⁱ will be added to obtain a vector, and each element of this vector will be divided by N The resulting new vector is the final linear relationship error vector e ⁱ . The vector g ⁱ is equal to the final error vector e ⁱ . Save the vector g ⁱ on the computer hard disk running the health monitoring system software for use by the health monitoring system software. Save all obtained parameters as data files on the hard disk of the computer running the health monitoring system software.

Step 10: Obtain the current measured values of all specified monitored quantities of the cable structure through actual measurement, and form a "current value vector C ⁱ of the monitored quantities". The current cable forces of all the supporting cables of the cable structure are measured to form the current cable force vector F ⁱ . The spatial coordinates of the two supporting end points of all supporting cables are obtained through actual measurement and calculation, and the difference in the horizontal component of the spatial coordinates of the two supporting end points is the horizontal distance between the two supporting end points.

Step 11: Conduct non-destructive testing on the newly added M ₂ cables, such as ultrasonic flaw detection, visual inspection, and infrared imaging inspection, to identify damaged or loose cables.

Step 12: According to the numbering rule of the monitored quantity, remove the element corresponding to the damaged or loose cable identified in the eleventh step from the initial value vector C ⁱ _o of the monitored quantity; according to the numbering rule of the monitored quantity, Remove the row corresponding to the damaged or loose cable identified in the eleventh step from the numerical change matrix ΔC ⁱ of the monitored quantity per unit damage; remove from the current numerical vector C ⁱ of the monitored quantity according to the numbering rule of the monitored quantity The element corresponding to the damaged or loose cable identified in the eleventh step; according to the numbering rule of the monitored quantity, remove the element corresponding to the damaged or loose cable identified in the eleventh step from the vector g.

Step 13: According to the "current numerical vector C ⁱ of the monitored quantity" and "the initial numerical vector C ⁱ _o of the monitored quantity", "the change matrix ΔC ⁱ of the monitored quantity for unit damage" and "the current nominal health state vector d ⁱ _c " exists an approximate linear relationship (Formula (9)), according to the multi-objective optimization algorithm to calculate the non-inferior solution of the current nominal health state vector d ⁱ _c of the cable system.

There are many kinds of multi-objective optimization algorithms that can be used, such as: multi-objective optimization based on genetic algorithm, multi-objective optimization based on artificial neural network, multi-objective optimization algorithm based on particle swarm, multi-objective optimization based on ant colony algorithm, constraint method (Constrain Method), Weighted Sum Method, Goal Attainment Method, etc. Since various multi-objective optimization algorithms are conventional algorithms, they can be easily implemented. This implementation step only uses the goal programming method as an example to give the process of solving the current nominal health state vector d ⁱ _c . The specific implementation process of other algorithms can be based on other The requirements of specific algorithms are implemented in a similar manner.

According to the objective programming method, Equation (9) can be transformed into the multi-objective optimization problem shown in Equation (29) and Equation (30). In Equation (29), γ ⁱ is a real number, R is a real number field, and the spatial region Ω limits The value range of each element of the vector d ⁱ _c (this embodiment requires that each element of the vector d ⁱ _c is not less than 0 and not greater than 1). Equation (29) means to find a real number γ ⁱ with the smallest absolute value, so that Equation (30) is satisfied. G(d ⁱ _c ) in formula (30) is defined by formula (31), and the product of weighted vector W ⁱ and γ ⁱ in formula (30) represents the relationship between G(d ⁱ _c ) and vector g ⁱ in formula (30) The definition of allowable deviation, g ⁱ can be found in formula (15), and its value is calculated in the eighth step. The vector W ⁱ may be the same as the vector g ⁱ in actual calculation. The specific programming implementation of the goal programming method already has a general program that can be directly adopted. According to the goal programming method, the current nominal health state vector d ⁱ _c can be obtained.

minimizeγ ⁱ (29)

γ ⁱ ∈ R, $d_c^i\&Element;\mathrm{\&Omega;}$

$G\left(d_c^i\right)-W^i{\mathrm{\&gamma;}}^i\&le;g^i$ (30)

$G\left(d_c^i\right)=\mathrm{abs}({\mathrm{\&Delta;C}}^i\&Center\; Dot;d_c^i-C^i+C_o^i)$ (31)

After the current nominal health state vector d ⁱ _c is obtained, each element of the current actual health state vector d ⁱ can be obtained according to formula (17). The current actual health state vector d ⁱ has a reasonable error, but can be identified more accurately The cable in question (which may be damaged or slack), can determine the solution of all support displacements with relative accuracy. Each element of d ⁱ corresponds to the health status of an evaluated object. If the evaluated object is a cable (or tie rod) in the cable system, then the value of this element indicates its current damage or relaxation. If the evaluated object The object is a displacement component of a support, then the value of this element represents its current displacement value.

Step Fourteen: Identify damaged and slack cords. Since the element value of the current actual health state vector d ⁱ represents the current actual health state of the corresponding evaluated object, if an element d ⁱ _j of d ⁱ corresponds to a cable (or tie rod) in the cable system, then d ⁱ _j represents Its current possible actual damage, when d ⁱ _j is 0, it means no damage, when it is 100%, it means that the cable completely loses its bearing capacity, when it is between 0 and 100%, it means that it loses the corresponding proportion of bearing capacity, but this cable What is the occurrence of damage or relaxation, need to be identified. There are various identification methods, such as visual identification of the support cable by removing the protective layer of the support cable, or visual identification with the help of optical imaging equipment, or identification of whether the support cable is damaged by non-destructive testing methods, ultrasonic Flaw detection is a non-destructive testing method widely used at present. After the identification, those support cables with no damage found and the value of d ⁱ _j not equal to 0 are the cables with slack, that is, the cables whose force needs to be adjusted. According to formula (24) or formula (25), the degree of relaxation of these cables can be obtained (i.e. cable length adjustment). This enables damaged and slack cable identification.

Step 15: Identify the bearing displacement. The element value corresponding to the support displacement of the current actual health state vector d ⁱ is the support displacement.

Step 16: After obtaining the current nominal health state vector d ⁱ _c in this cycle, that is, the i-th cycle, establish the identification vector B ⁱ according to formula (26) and formula (27). If the elements of the identification vector B ⁱ are all 0, then go back to the tenth step to continue this cycle; if the elements of the identification vector B ⁱ are not all 0, then enter the next step, that is, the fifteenth step.

Step 17: Calculate and obtain each _element d i+1 oj of the initial damage vector d ⁱ⁺¹ _o required for the next cycle, that is, the ⁱ⁺ 1th cycle, according to formula (28).

Step 18: On the basis of the cable structure mechanical calculation benchmark model A ⁱ , let the health status of the evaluated object be the vector d ⁱ⁺¹ _o calculated in the previous step, and obtain a new mechanical calculation benchmark model, that is, the next The mechanical calculation benchmark model A i ⁺¹ required for the (i+1th) cycle.

Step 19: Obtain the values of all the monitored quantities corresponding to the structure of the model A ⁱ⁺¹ through the calculation of the mechanical calculation benchmark model A ⁱ⁺¹ , and these values constitute the requirements for the next cycle, that is, the i+1th cycle The vector C ⁱ⁺¹ _{o of} is the initial numerical vector of the monitored quantity.

Step 20: The computer in the health monitoring system generates reports on the health status of the cable system automatically or by personnel operating the health monitoring system on a regular basis.

The twenty-first step: under the specified conditions, the computer in the health monitoring system automatically operates the communication alarm equipment to alarm the monitoring personnel, the owner and (or) the designated personnel.

Step 22: Go back to Step 7 and start the next cycle.

Claims (2)

1. health monitoring method of increment cable structure based on cable force monitoring is characterized in that described method comprises:

A. claim that evaluated support cable and support displacement component are evaluation object, establishing the quantity of evaluated support cable and the quantity sum of support displacement component is N, and promptly the quantity of evaluation object is N; Determine the coding rule of evaluation object, with evaluation object numberings all in the Cable Structure, this numbering will be used to generate the vector sum matrix in subsequent step by this rule; Represent this numbering with variable j, j=1,2,3 ..., N;

B. establish total Q root support cable in the cable system, structure rope force data comprises the Suo Li of this Q root support cable, and obviously Q is less than the quantity N of evaluation object; Only the state of finding the solution N unknown evaluation object by Q rope force data of Q support cable is impossible, supports on the basis of cable forces at the whole Q roots of monitoring, structurally artificially increases M ₂The root rope will be monitored the M that this increases newly in the monitoring structural health conditions process ₂The Suo Li of root rope; Comprehensive above-mentioned monitored amount, M Suo Li of the total M root rope of total is monitored, and M monitored amount promptly arranged, and wherein M is Q and M ₂Sum; M must not be less than the quantity N of evaluation object; The M that increases newly ₂The rigidity of root rope is compared with the rigidity of any support cable of Cable Structure, should be much smaller; The M that increases newly ₂The Suo Li of root rope should be more much smaller than the Suo Li of any support cable of Cable Structure, even can guarantee the M that this increases newly like this ₂Damage or lax has appearred in the root rope, and is very little to the influence of the stress of other members of Cable Structure, strain, distortion; The M that increases newly ₂Normal stress should be less than its fatigue limit on the xsect of root rope, and these requirements can guarantee the M that increases newly ₂Fatigue damage can not take place in the root rope; The M that increases newly ₂The fully anchoring of the two ends of root rope guarantees can not occur relaxing; The M that increases newly ₂The root rope should obtain sufficient anti-corrosion protection, guarantees the M that increases newly ₂Damage and lax can not take place in the root rope; For simplicity, " all monitored parameters of structure " are abbreviated as " monitored amount "; Give M monitored amount serial number, this numbering will be used to generate the vector sum matrix in subsequent step;

C. the data of utilizing the Non-Destructive Testing data etc. of evaluation object can express the health status of evaluation object are set up evaluation object initial health vector d ⁱ _oIf when not having the Non-Destructive Testing data of evaluation object, vectorial d ⁱ _oEach element numerical value get 0; Vector d ⁱ _oThe coding rule of element and the coding rule of evaluation object identical; Represent cycle index with i, i=1,2,3 ...; Here be circulation for the first time, i gets 1, the initial health vector d that promptly sets up here ⁱ _oCan be embodied as d ¹ _o

D. setting up initial health vector d ¹ _oThe time, directly measurement calculates the initial value of all monitored amounts of Cable Structure, forms the initial value vector C of monitored amount ⁱ _oHere be circulation for the first time, i gets 1, i.e. the initial value of the monitored amount of setting up here vector C ⁱ _oCan be embodied as C ¹ _oObtain monitored amount initial value vector C in actual measurement ¹ _oThe time, actual measurement obtains the initial geometric data and the initial Cable Structure support coordinate data of Cable Structure; Directly measure the initial Suo Li that calculates all support cables, form initial rope force vector F _oSimultaneously, obtain the initial drift of all support cables, form initial drift vector l according to structural design data, completion data _oVector F _oWith vectorial l _oBe constant; Simultaneously, survey or obtain elastic modulus, density, the initial cross sectional area of all ropes according to structural design, completion information;

E. according to the measured data of design drawing, as-constructed drawing and the Cable Structure of Cable Structure, the Non-Destructive Testing data of rope and the Mechanics Calculation benchmark model A that initial Cable Structure support coordinate data are set up Cable Structure ⁱHere be circulation for the first time, i gets 1, i.e. the Mechanics Calculation benchmark model A of the Cable Structure of setting up here ⁱCan be embodied as A ¹

F. at Mechanics Calculation benchmark model A ⁱThe basis on carry out the several times Mechanics Calculation, by calculate obtaining " unit damage monitored numerical quantity transformation matrices Δ C ⁱ" and " nominal unit damage vector D ⁱ _u";

G. actual measurement obtain Cable Structure all specify the current measured value of monitored amount, form " the current numerical value vector C of monitored amount ⁱ"; When numbering to the element of the institute's directed quantity that occurred before this step and this step, should use same coding rule, can guarantee the element each vector, that numbering is identical that occurs before this step and this step like this, represent same monitored amount, corresponding to vectorial defined relevant information under this element; Actual measurement obtains the current cable power of all support cables of Cable Structure, forms current cable force vector F ⁱActual measurement calculates the volume coordinate of two supporting end points of all support cables, and the volume coordinate of two the supporting end points difference of component in the horizontal direction is exactly two supporting end points horizontal ranges;

H. in the monitoring structural health conditions process, to the M that increases newly ₂Root Suo Jinhang Non-Destructive Testing therefrom identifies the rope that damage occurs or relax;

I. according to monitored amount coding rule, from the initial value vector C of monitored amount ⁱ _oThe middle element of removing appearance damage that identifies among the step h or the rope correspondence that relaxes; According to monitored amount coding rule, from unit damage monitored numerical quantity transformation matrices Δ C ⁱThe middle row of removing appearance damage that identifies among the step h or the rope correspondence that relaxes;

J. define current nominal health status vector d ⁱ _cWith current actual health status vector d ⁱ, the element number of two damage vectors equals the quantity of evaluation object, current nominal health status vector d ⁱ _cElement numerical value represent the current nominal degree of injury or the support displacement of corresponding evaluation object, current actual health status vector d ⁱElement numerical value represent the current actual damage degree or the support displacement of corresponding evaluation object, the element number of the element of two damage vectors equals the quantity of evaluation object, between the element of two damage vectors and the evaluation object is one-to-one relationship, and the coding rule of the element of two damage vectors is identical with the coding rule of evaluation object;

K. according to " the current numerical value vector C of monitored amount ⁱ" " the initial value of monitored amount vector C together ⁱ _o", " unit damage monitored numerical quantity transformation matrices Δ C ⁱ" and " current nominal health status vector d ⁱ _c" between the linear approximate relationship that exists, this linear approximate relationship can be expressed as formula 1, removes d in the formula 1 ⁱ _cOther outer amount is known, finds the solution formula 1 and just can calculate current nominal health status vector d ⁱ _c

Formula 1

L. the current actual health status vector d that utilizes formula 2 to express ⁱWith initial health vector d ⁱ _oWith current nominal health status vector d ⁱ _cElement between relation, calculate current actual health status vector d ⁱAll elements;

Formula 2

J=1 in the formula 2,2,3 ..., N;

Current actual health status vector d ⁱElement numerical value represent the actual damage degree or the actual support displacement of corresponding evaluation object, according to current actual health status vector d ⁱJust can define the impaired and degree of injury of which rope, just can determine actual support displacement; If a certain element of current actual health status vector is corresponding to a rope in the cable system, and its numerical value is 0, represent that the pairing rope of this element is intact, not damage or lax, if its numerical value is 100%, represent that then the pairing rope of this element has completely lost load-bearing capacity, lost the load-bearing capacity of corresponding proportion if its numerical value between 0 and 100%, is then represented this rope; If a certain element of current actual health status vector is corresponding to displacement component, a d so of a bearing ⁱ _jRepresent its present bit shift value;

M. the problematic literary composition that identifies the step from l holds and identifies damaged cable in the rope, and remaining is exactly slack line;

N. utilize the current actual health status vector d that obtains in the l step ⁱObtain the current actual virtual lesion degree of slack line, utilize the current cable force vector F that obtains in the g step ⁱ, utilize two horizontal ranges that support end points in all support cables of g step acquisition, utilize the vectorial l of the initial drift that obtains in the d step _oUtilization is in elastic modulus, density, the initial cross sectional area data of all ropes of d step acquisition, by with slack line with damaged cable carry out the mechanics equivalence calculate slack line, with the relax level of current actual virtual lesion degree equivalence, the mechanical condition of equivalence is: one, the mechanics parameters of lax initial drift, geometrical property parameter, density and the material during with not damaged of the nothing of the rope of two equivalences is identical; Two, after the lax or damage, the Suo Li of the slack line of two equivalences and damage rope be out of shape after length overall identical; When satisfying above-mentioned two equivalent conditions, the such mechanics function of two support cables in structure is exactly identical, if after promptly replacing damaged cable with the slack line of equivalence, Cable Structure any variation can not take place, vice versa; Try to achieve the relax level that those are judged as slack line according to aforementioned mechanics equivalent condition, relax level is exactly the change amount of support cable drift, has just determined the long adjustment amount of rope of the support cable that those need adjust Suo Li; So just realized the lax identification of support cable; Institute's demand power is by current cable force vector F during calculating ⁱCorresponding element provides;

O. try to achieve current nominal health status vector d ⁱ _cAfter, set up mark vector B according to formula 3 ⁱ, formula 4 has provided mark vector B ⁱThe definition of j element;

Formula 3

Formula 4

Element B in the formula 4 ⁱ _jBe mark vector B ⁱJ element, D ⁱ _UjBe nominal unit damage vector D ⁱ _uJ element, d ⁱ _CjBe current nominal health status vector d ⁱ _cJ element, they all represent the relevant information of j evaluation object, j=1 in the formula 4,2,3 ..., N;

If mark vector B p. ⁱElement be 0 entirely, then get back to g step and continue this circulation; If mark vector B ⁱElement be not 0 entirely, then enter next step, i.e. q step;

Q. according to formula 5 calculate next time, i.e. the i+1 time required initial health of circulation vector d ^I+1 _oEach element d ^I+1 _Oj

Formula 5

D in the formula 5 ⁱ _UjBe nominal unit damage vector D ⁱ _uJ element, d ⁱ _CjBe current nominal health status vector d ⁱ _cJ element, B ⁱ _jBe mark vector B ⁱJ element, j=1 in the formula 5,2,3 ..., N; Vector d ^I+1 _oThe coding rule of element and the coding rule of evaluation object identical;

R. at Mechanics Calculation benchmark model A ⁱThe basis on, the health status that makes evaluation object is d ^I+1 _oThe back renewal obtains next time, required Mechanics Calculation benchmark model A promptly circulates for the i+1 time ^I+1

S. pass through Mechanics Calculation benchmark model A ^I+1Calculate corresponding to model A ^I+1Structure all monitored strains point, with the monitored strain numerical value that should change direction, these numerical value are formed next time, the vectorial C of initial value of the required monitored amount that promptly circulates for the i+1 time ^I+1 _o

T. get back to the f step, beginning is circulation next time.

2. the health monitoring method of increment cable structure based on cable force monitoring according to claim 1 is characterized in that in step f, at Mechanics Calculation benchmark model A ⁱThe basis on carry out the several times Mechanics Calculation, by calculate obtaining " unit damage monitored numerical quantity transformation matrices Δ C ⁱ" and " nominal unit damage vector D ⁱ _u" concrete grammar be:

F1. at the Mechanics Calculation benchmark model A of Cable Structure ⁱThe basis on carry out the several times Mechanics Calculation, equal N on the calculation times numerical value; Coding rule according to evaluation object calculates successively; Calculating hypothesis each time has only an evaluation object to increase unit damage or unit displacement again on the basis of original damage or displacement, concrete, if this evaluation object is a support cable in the cable system, so just suppose that this support cable increases unit damage again, if this evaluation object is the displacement component of a direction of a bearing, just suppose that this bearing increases unit displacement again at this sense of displacement, the evaluation object that increases unit damage or unit displacement in calculating each time again is different from the evaluation object that increases unit damage or unit displacement in other time calculating again, with " nominal unit damage vector D ⁱ _u" write down the unit damage or the unit displacement that increase again of all supposition; wherein i represents the i time circulation; calculate the current calculated value that all utilizes mechanics method to calculate all monitored amounts of Cable Structure each time, and monitored amount of current calculated value composition of the monitored amount of all that calculate is calculated current numerical value vector each time;

F2. the monitored amount that calculates is each time calculated and is calculated unit damage or the unit displacement numerical value of being supposed divided by this time again after current numerical value vector deducts monitored amount initial value vector, obtain a monitored quantitative change vector, have N evaluation object that N monitored quantitative change vector just arranged;

F3. by the coding rule of this N monitored quantitative change vector, form the Cable Structure unit damage monitored numerical quantity transformation matrices Δ C that the N row are arranged successively according to N evaluation object ⁱ