CN101793628B - Cable structure health monitoring method based on hybrid monitoring - Google Patents

Abstract

A cable structure health monitoring method based on hybrid monitoring. This method is based on hybrid monitoring, and establishes a mechanical calculation benchmark model of the cable structure based on the cable structure design drawing, as-built drawing, and actual measurement data of the cable structure. On the basis of the mechanical calculation benchmark model Several mechanical calculations are performed on the cable structure, and the unit change matrix of the monitored quantity of the cable structure is obtained through calculation. According to the approximate linear relationship between the current numerical vector of the monitored quantity and the initial vector of the monitored quantity, the unit change matrix of the monitored quantity of the cable structure, and the current health state vector of the evaluated object, the health status of the cable structure can be identified. Changes, i.e. bearing displacement, damaged and slack cables are identified.

Description

A Health Monitoring Method for Cable Structures Based on Hybrid Monitoring

technical field

The invention is based on structural health monitoring technology, based on hybrid monitoring to identify support displacement, identify damaged cables in the cable system of the cable structure, identify supporting cables that need to adjust the cable force, and provide specific cable length adjustments, which belongs to engineering field of structural health monitoring.

Background technique

The displacement of the support is a major threat to the safety of the cable structure. Similarly, the damage and relaxation of the cable system will also have a negative impact on the safety of the structure. In severe cases, it will cause the failure of the structure. Damaged cables and slack cables (i.e. support cables whose tension needs to be adjusted) are very necessary.

The change of the measurable parameters of the structure, such as the change of the cable force, the deformation or strain of the cable structure, and the shape or spatial coordinates of the cable structure, will be caused by the support displacement, damaged cable and loose cable of the cable structure. , will cause the change of the angular coordinate of any imaginary straight line passing through each point of the cable structure (for example, the change of the angular coordinate of any straight line passing through the point in the tangent plane of any point on the structure surface, or the normal Changes in the angular coordinates of the lines), all of these changes include the health status information of the cable system, so the health status of the structure can be judged by the mixed monitoring of the changes in the characteristic parameters of these different types of structures. The present invention combines all The monitored structural characteristic parameters are collectively referred to as "monitored quantities". Since the monitored quantities are composed of a mixture of different types of measurable parameters of the structure, the present invention calls this mixed monitoring, which means that mixed monitoring can be used to identify Bearing displacement, damaged and slack cables.

Contents of the invention

Technical problem: The present invention discloses a cable structure health monitoring method based on hybrid monitoring, which can reasonably and effectively identify bearing displacement, damaged cable and slack cable 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 It is a kind of threat. 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 is damaged, such as local cracks and corrosion in the support cable, etc.; The supporting cable is not damaged, but the cable force has also changed. One of the main reasons for this change is the cable length (called the free length, The present invention refers specifically to the free length of that section of cable between the two supporting end points of the supporting cable) has changed; the third is that the supporting cable is not damaged, but the cable structure support has displacement (wherein the component in the direction of gravity is just called settlement ), it will also cause the change of the internal force of the structure, and of course it will also cause the change of the cable force. For convenience, in the present invention, the support cables whose free length changes are collectively referred to as slack cables.

The present invention is made up of two major parts. They are respectively: 1. A method for establishing the knowledge base and parameters required by the health monitoring system for identifying bearing displacement, damaged cables and slack cables, based on the knowledge base (including parameters), and based on the monitoring of the monitored quantity and the like , A method for identifying support displacements, damaged cables, and slack cables of cable structures. Second, the software and hardware parts of the health monitoring system.

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 cable and bearing displacement as "the evaluated object", and the evaluated object is serially numbered, and the present invention represents this numbering with the variable i, i=1,2,3, ..., N, so let's say there are N objects being evaluated.

The first part of the present invention: a method for establishing the knowledge base and parameters required by the health monitoring system for identifying the cable structure support displacement, damaged cable and slack cable, based on the knowledge base (including parameters), based on the actual measured cable structure support Coordinated, monitoring based on monitored quantity equivalence, method for identifying support displacements, damaged cables and slack cables of cable structures. To obtain a more accurate assessment of the health status of the cable structure, proceed as follows.

Step 1: first establish the initial health state vector d _o of the cable structure, and establish the initial mechanical calculation benchmark model A _o of the cable structure (for example, the finite element benchmark model, A _o is constant in the present invention).

The "initial health state vector of the cable structure is denoted as d _o " (as shown in formula (1)), and d _o represents the health state of the cable structure (expressed by the initial mechanical calculation benchmark model A _o of the cable structure).

d _o ＝[d _o1 d _o2 ···d _oi ···d _oN ] ^T (1)

In formula (1), d _oi (i=1, 2, 3, ..., N) represents the initial health status of the i-th evaluated object of the cable structure in A _o , if the evaluated object is a cable (or tie rod) in the cable system, then d _oi represents its initial damage, when d _oi is 0, it means no damage, and when it is 100%, it means that the cable completely loses its bearing capacity, between 0 and 100% When , it means that the bearing capacity of the corresponding proportion is lost. If the cable is found to be undamaged by non-destructive testing, then d _oi means that the cable is mechanically equivalent to the damage value of d _oi . The evaluation object is a displacement component of a support, then d _oi represents its initial displacement value. In formula (1), T represents the transposition of the vector (the same below).

When establishing the initial health state vector of the cable structure (recorded as d _o according to the formula (1), use the actual measurement data of the support coordinates of the cable structure when the cable structure is completed or when the health monitoring system starts to work, as well as design drawings and as-built drawings Determine the value of each element of the cable structure initial health state vector d _o corresponding to the support displacement; use the non-destructive testing data of the cable and other data that can express the health state of the cable to determine the initial health state vector _do of the cable structure corresponding to each cable Element value; if there is no non-destructive testing data of the cable and other data that can express the health 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 of the vector d _o corresponding to the cable is set to 0.

The method of establishing the mechanical calculation benchmark model A _o (such as the finite element benchmark model) of the cable structure is as follows:

When establishing A _o , 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, tension rod tension data, cable structure support coordinate data, cable structure modal data and other measured data, the oblique For stayed bridges and suspension bridges, it refers to bridge type data, cable force data, bridge modal data, cable non-destructive testing data and other data that can express the health status of cables), design drawings, as-built drawings, using mechanical methods (such as finite element method) to establish 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 is 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, it is the bridge type data, cable force data, bridge modal data, Data and other data that can express the health status of the cable), 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 .

The multi-type parameters to be monitored may include: cable force, strain, angle and spatial coordinates, which are described as follows:

Assuming that there are Q cables in the cable system, the monitored cable force data of the structure is described by M ₁ cable force data of M ₁ specified cables on the structure, and the change of the structural cable force is the change of the cable force of all specified cables. Each time there are _M1 cable force measurements or calculations to represent the cable force information of the structure. M ₁ is an integer not less than 0.

The monitored strain data of the structure can be described by the strains of K ₂ designated points on the structure and L ₂ designated directions of each designated point. The change of the structural strain data is the sum of all the measured strains of the K ₂ designated points Variety. Each time there are M ₂ (M ₂ =K ₂ ×L ₂ ) measured or calculated strain values to characterize the structural strain. M ₂ is an integer not less than 0.

The monitored angle data of the structure is described by K ₃ designated points on the structure, L ₃ designated straight lines passing through each designated point, and H ₃ angular coordinate components of each designated straight line. The change of the structural angle is all Change of the specified point, of all specified lines, of all specified angular coordinate components. Each time there are M ₃ (M ₃ =K ₃ ×L ₃ ×H ₃ ) measured or calculated values of the angle coordinate components to represent the angle information of the structure. M ₃ is an integer not less than 0.

The monitored shape data of the structure is described by the spatial coordinates of K ₄ designated points on the structure and L ₄ designated directions of each designated point. The change of the structural shape data is the coordinate component of all the K ₄ designated points. Variety. Each time there are M ₄ (M ₄ =K ₄ ×L ₄ ) coordinate measurements or calculation values to characterize the shape of the structure. M ₄ is an integer not less than 0.

Based on the above-mentioned monitored quantities, the entire structure has a total of M (M=M ₁ +M ₂ +M ₃ +M ₄ ) monitored quantities, and the defined parameter K (K=M ₁ +K ₂ +K ₃ +K ₄ ), K and M must not be less than the number N of objects being evaluated. Since the M monitored quantities are of different types, the present invention is called "a cable structure health monitoring method based on hybrid monitoring".

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

In the present invention, the initial vector C _o of the monitored quantity is used to represent the vector composed of the initial values of all the monitored quantities of the cable structure (see formula (2)). It is required to obtain C _o while obtaining A _o . Because under the aforementioned conditions, the monitored quantity calculated based on the calculation reference model of the cable structure is reliably close to the measured data of the initial monitored quantity, in the following description, the calculated value and the measured value will be represented by the same symbol.

C _o ＝[C _o1 C _o2 ···C _oj ···C _oM ] ^T (2)

In formula (2), C _oj (j=1, 2, 3,..., M; M≥N) is the initial quantity of the jth monitored quantity in the cable structure, and this component corresponds to For the specific jth monitored quantity. T represents the transpose of the vector (the same below).

The current value vector C of the monitored quantity used in the present invention is a vector composed of the current values of all the monitored quantities in the cable structure (see formula (3) for definition).

C＝[C ₁ C ₂ ···C _j ···C _M ] ^T (3)

In formula (3), C _j (j=1, 2, 3,..., M; M≥N) is the current value of the jth monitored quantity in the cable structure, and the component C _j is based on the number The rules correspond to the same "monitored quantity" as C _oj .

The second step: the method of establishing the unit change matrix ΔC of the monitored quantity of the cable structure.

Several calculations are performed on the basis of the mechanical calculation benchmark model A _o of the cable structure, and the number of calculations is numerically equal to N. Each calculation assumes that there is only one evaluated object on the basis of the original health state (represented by the initial health state vector d _o of the cable structure) with unit damage or unit displacement (the present invention is called health state with unit change, or simply with unit change), specifically, if the evaluated object is a support cable in the cable system, then it is assumed that the support cable increases unit damage (for example, 5%, 10%, 20% or 30% damage is taken as unit damage) , if the evaluated object is the displacement component of a support in one direction, it is assumed that the support increases in the direction of displacement and has a unit displacement (for example, 10mm, 20mm, 30mm, etc. as the unit displacement), and use Du _ui to record this unit damage or unit displacement, where i represents the number of the assessed object hypothetically increasing the occurrence of unit damage or unit displacement. All unit damages or unit displacements are recorded by "unit damage or unit displacement vector D _u " (as shown in equation (4)). The evaluated object with unit damage or unit displacement in each calculation is different from the evaluated object with unit damage or unit displacement in other calculations. Each calculation uses mechanical methods (such as finite element method) to calculate all the evaluated objects of the cable structure. The current calculated value of the monitored quantity, the current calculated value of all the monitored quantities obtained by each calculation forms a calculated current vector of the monitored quantity (when it is assumed that the i-th monitored quantity has unit damage or unit displacement, formula (5) can be used Indicates the calculated current vector of the monitored quantity (C _t ⁱ ); each calculation obtains the calculated current vector of the monitored quantity minus the initial vector of the monitored quantity, and then divides it by the assumed unit damage or unit displacement value of this calculation, and the obtained vector is this Under the conditions (marked by the number of the assessed object with unit damage or unit displacement) the change vector of the monitored quantity (when the i-th assessed object has unit damage or unit displacement, use δC _i to represent the change vector of the monitored quantity , see formula (6) for the definition, formula (6) is obtained by subtracting formula (2) from formula (5), and each element of the monitored quantity change vector represents the one that is estimated due to the assumption of unit damage or unit displacement during calculation The change of the monitored quantity corresponding to the element caused by the unit change of the object; there are N monitored quantity change vectors if there are N evaluated objects. Since there are M monitored quantities, each monitored quantity changes The vector has M elements, and the N monitored quantity change vectors form the monitored quantity unit change matrix ΔC with M×N elements in turn. The definition of ΔC is shown in formula (7).

D _u ＝[D _u1 D _u2 ···D _ui ···D _uN ] ^T (4)

The element D _ui (i=1, 2, 3, ..., N) of the unit damage or unit displacement vector D _u in formula (4) represents the unit damage or unit displacement value of the i-th evaluated object , the value of each element in the vector D _u can be the same or different.

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>{\left[\begin{array}{cccccccccc}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&CenterDot;</span>& <span\; class="notranslate">\; \&CenterDot;</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tj</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; \&CenterDot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&CenterDot;</span>& {\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; tM</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]}^{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Element C _tj ⁱ in formula (5) (i=1, 2, 3, ..., N; j = 1, 2, 3, ..., M; M≥N) Indicates the current calculated amount of the jth monitored quantity corresponding to the numbering rule when the ith assessed object has unit damage or unit displacement.

${\mathrm{<span\; class="notranslate">\; \&delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}^{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; ui</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

$\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cccccc}{\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; 1,1</span>}}& \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1,2</span>}}& <span\; class="notranslate">\; \&Center\; Dot;</span>& \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; \&CenterDot;</span>& \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; 2,1</span>}}& \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 2,2</span>}}& <span\; class="notranslate">\; \&CenterDot;</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; \&CenterDot;</span>& \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}}\\ <span\; class="notranslate">\; \&CenterDot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&CenterDot;</span>& <span\; class="notranslate">\; \&CenterDot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>\\ {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}& {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}}& <span\; class="notranslate">\; \&CenterDot;</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; \&Center\; Dot;</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}}\\ <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&CenterDot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>& <span\; class="notranslate">\; \&Center\; Dot;</span>\\ {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}& \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}}& <span\; class="notranslate">\; \&Center\; Dot;</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}}& <span\; class="notranslate">\; \&Center\; Dot;</span>& {\mathrm{<span\; class="notranslate">\; \&Delta;C</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}}\end{array}\right]<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>$

In formula (7), ΔC _{j, i} (i=1, 2, 3, ..., N; j = 1, 2, 3, ..., M; M≥N) Indicates the change (algebraic value) of the calculated current value of the j-th monitored quantity corresponding to the numbering rule only due to the unit change (unit damage or unit displacement) of the i-th assessed object. The monitored variable change vector δC _i is actually a column in the matrix ΔC, and ΔC can also be defined by δC _i , as in formula (8).

ΔC=[δC ₁ δC ₂ ···δC _i ···δC _N ] (8)

The vector δC _i (i=1, 2, 3, ..., N) in formula (8) represents the _relative Value changes. The numbering rule of the column (subscript i) of the matrix ΔC is the same as the numbering rule of the subscript i of the elements of the previous vector d _o .

The third step: during the service process of the cable structure, the current data of the monitored quantity of the cable structure is continuously measured to form the "current (calculated or measured) numerical vector C of the monitored quantity" of the cable structure.

Step 4: Identify the current state of health of the cable structure (identify bearing displacement, damaged cables, and slack cables). The specific process is as follows.

The approximate linear relationship between the current numerical vector C (calculated or measured) of the monitored quantity and the initial vector C _o of the monitored quantity, the unit change matrix ΔC of the monitored quantity, and the current health state vector d of the evaluated object, such as formula (9) or formula (10) shown.

C＝C _o +ΔC d _c (9)

CC _o =ΔC d _c (10)

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

C＝[C ₁ C ₂ ···C _j ···C _M ] ^T (11)

The element C _j (j=1, 2, 3,..., M; M≥N) in the formula (11) is the monitored quantity of the number j corresponding to the cable structure and according to the numbering rules current value.

d _c ＝[d _c1 d _c2 ··· d _ci ··· d _cN ] ^T (12)

In formula (12), d _ci (i=1, 2, 3, . . . , N) is the current health status of the i-th evaluated object in the cable structure. The numbering rule of the subscript i of the elements of the vector d _c is the same as that of the columns of the matrix ΔC.

When the actual damage of the cable 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, and the error of such a linear relationship represented by formula (9) or formula (10) is relatively small compared with the actual situation. Small, the error can be defined by the error vector e (Equation (13)), which represents the error of the linear relationship shown in Equation (9) or Equation (10).

e=abs(ΔC d _c -C+C _o ) (13)

In the formula (13), abs() 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 directly solved according to formula (9) or formula (10) and "the current (measured) value vector C of the monitored quantity" to obtain "The current health state vector d _c of the evaluated object". If this is done, the elements in the obtained vector _dc may even have relatively large negative values, that is, negative damage, negative relaxation or negative support settlement, which is obviously unreasonable. Therefore, obtaining an acceptable solution of the vector d _c (that is, with reasonable error, but which can determine the displacement of the support relatively accurately, determine the position of the damaged cable and its degree of damage, determine the position of the slack cable and its degree of slack) becomes a Reasonable solution, available formula (14) to express this method.

abs(ΔC d _c -C+C _o )≤g (14)

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

g＝[g ₁ g ₂ ···g _j ···g _M ] ^T (15)

g _j (j=1, 2, 3, . . . , M) in formula (15) describes the maximum allowable deviation from the ideal linear relationship shown in formula (9) or formula (10). The vector g can be selected according to the error vector e defined by formula (13).

After the "initial numerical vector C _o of the monitored quantity" (obtained by actual measurement or calculation), "the unit change matrix ΔC of the monitored quantity of the cable structure" (obtained by calculation) and "the current numerical vector C of the monitored quantity" (obtained by actual measurement) have been When the time is known, an appropriate algorithm (such as a multi-objective optimization algorithm) can be used to solve formula (14) to obtain an acceptable solution of "the current health state vector d _c of the evaluated object", and then the "current actual health state vector d" (definition The elements of formula (16)) can be calculated according to formula (17), that is, the "current actual health state vector d" is obtained, and the current actual health state vector d expresses the actual health state of the cable structure included in the initial health state .

d=[d ₁ d ₂ ··· d _i ··· d _N ] ^T (16)

In formula (16), d _i (i=1, 2, 3, ..., N) represents the current actual health status of the i-th evaluated object of the cable structure, if the evaluated object is a cable system A cable (or tie rod) in , then d _i represents its current actual damage, 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 Lose the bearing capacity of the corresponding proportion; after the damaged cable is determined, carry out non-destructive testing on all the damaged cables. After the non-destructive testing, 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 , given by This determines the slack cable, and the calculation method of the specific slack amount is explained below; if the evaluated object is a displacement component of a support, then d _i represents its current displacement value. The numbering rules of the elements of the vector d are the same as the numbering rules of the elements of the vector do in formula (1).

d _i ＝1-(1-d _oi )(1-d _ci ) (17)

In the formula (17), d _oi (i=1, 2, 3, . . . , N) is the jth element of the vector d _o , and d _cj is the jth element of the vector d _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.

Assuming that there are Q supporting cables in the cable system, the structural cable force data is described by the cable force of Q supporting cables. The "initial cable force vector Fo" 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. By definition, vector C _o includes vector F _o .

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

F＝[F ₁ F ₂ ···F _k ···F _Q ] ^T (19)

In formula (19), F _k (k=1, 2, 3, . . . , Q) is the current cable force of the kth supporting cable in the cable structure.

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, and it will not change after it is determined at the beginning.

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

l＝[l ₁ l ₂ ···l _k ···l _Q ] ^T (21)

In formula (21), l _k (k=1, 2, 3, . . . , Q) is the current free length of the kth supporting cable in the cable structure.

In the present invention, the "free length change vector Δl" (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 (see formula (22) and formula (23) for definitions).

Δl=[Δl ₁ Δl ₂ ···Δl _k ···Δl _Q ] ^T (22)

In the formula (22), Δl _k (k=1, 2, 3, ..., Q) is the change of the free length of the kth supporting cable in the cable structure, and its definition is shown in the formula (23), The cable whose Δl _k is not 0 is a slack cable, and the value of Δl _k is the slack amount of the cable, which indicates the current slack degree of the k-th supporting cable of the cable system, and is also the cable length adjustment amount of the cable when the cable force is adjusted.

Δl _k ＝l _k -lo _k (23)

The numbering rules of the vectors F _o , d ^c , F _k , l _o , l, and Δl are the same.

After the slack cable is determined, in the present invention, the relaxation degree of the slack cable is identified by mechanically equivalent the slack cable to the damaged cable. 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 met, 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, the same support cable numbered k (its current degree of relaxation is defined by Δl _k , corresponding to the kth element of the vectors F _o , d ^c , F _k , l _o , l, Δl) undergoes equivalent receiving The current actual health state of the damaged support cable is denoted by d ^c _k (d ^c _k is the kth element of the current actual health state vector d ^c of the support cable). The relationship between the current relaxation degree Δl _k of the kth support cable (the definition of Δl _k is shown in formula (22)) and the current actual health state d ^c _k of the equivalent damaged cable is determined by the above two mechanical equivalent conditions Sure. The specific relationship between Δl _k and d ^c _k 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 based on Ernst equivalent elastic modulus instead of formula (24) E in is determined after correction (see formula (25)), and can also be determined by other methods such as trial algorithm based on finite element method.

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

${\mathrm{<span\; class="notranslate">\; \&Delta;l</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; c</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; c</span>}}}\frac{{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}{<span\; class="notranslate">\; [</span>\frac{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; k</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>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}{\mathrm{<span\; class="notranslate">\; 12</span>}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}}}}<span\; class="notranslate">\; ]</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; k</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), Ek is the elastic modulus of the supporting cable, A _k is the cross-sectional area of the supporting cable, F _k is the current cable force of the supporting cable, d ^c _k is the The current actual health status, ω _k is the weight per unit length of the support cable, and l _kx is the horizontal distance between the two support ends of the support cable. The term in [] in formula (25) is the Ernst equivalent elastic modulus of the support cable, and the current relaxation degree vector Δl of the support cable can be determined from formula (24) or formula (25). Equation (25) is a modification of Equation (24).

The second part of the present invention: the software and hardware parts of the health monitoring system. The hardware part includes the monitoring system (monitoring the monitored quantity, monitoring the coordinates of the cable structure support, monitoring the cable force, and monitoring the horizontal distance between the two supporting ends of the supporting cable), signal collector and computer. It is required to monitor each monitored quantity in real time or quasi-real time, monitor the cable force of each supporting cable, and monitor the horizontal distance between the two supporting ends of each supporting cable. 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 represents this numbering with variable i , i=1, 2, 3, ..., N;

b. Determine the supporting cables that will be monitored for the cable forces specified during mixed monitoring. Suppose that there are Q cables in the cable system, and the monitored cable force data of the structure is obtained from the _M1 cable force data of the _M1 specified cables on the structure. Description, the change of the structural cable force is the change of the cable force of all specified cables; each time there are M ₁ cable force measured or calculated values to represent the cable force information of the structure; M ₁ is an integer not less than 0; determine the mixed The measured points to be monitored are specified during monitoring. The monitored strain data of the structure can be described by the strains of K ₂ designated points on the structure and L ₂ designated directions of each designated point. The structural strain data The change is the change of all measured strains at K ₃ specified points; each time there are M ₂ strain measurements or calculated values to characterize the structural strain, M ₂ is the product of K ₂ and L ₂ ; M ₂ is not less than 0 Integer; determine the point to be measured at the specified angle to be monitored during mixed monitoring, the monitored angle data of the structure consists of K ₃ specified points on the structure, L ₃ specified straight lines passing through each specified point, each specified The H ₃ angle coordinate components of the straight line are described, and the change of the structural angle is the change of all specified points, all specified straight lines, and all specified angle coordinate components; each time there are M ₃ angle coordinate component measured values or calculated values. Characterize the angle information of the structure, M ₃ is the product of K ₃ , L ₃ and H ₃ ; M ₃ is an integer not less than 0; the shape data to be monitored specified when determining the mixed monitoring, the monitored shape data of the structure Described by the spatial coordinates of K ₄ designated points on the structure and L ₄ designated directions of each designated point, the change of the structural shape data is the change of all coordinate components of the K ₄ designated points; each time there are M ₄ Coordinate measured values or calculated values to characterize the shape of the structure, M ₄ is the product of K ₄ and L ₄ ; M ₄ is an integer not less than 0; based on the monitored quantities of the above mixed monitoring, there are M monitored quantities in the entire structure , M is the sum of M ₁ , M ₂ , M ₃ and M ₄ , define the parameter K, K is the sum of M ₁ , K ₂ , K ₃ and K ₄ , K and M must not be less than the number N of the evaluated objects; because The M monitored quantities are of different types, so the present invention is called "a cable structure health monitoring method based on hybrid monitoring"; All parameters being monitored" are referred to as "monitored quantities";

c. Establishing an initial health state vector d _o using data that can express the health state of the cable, such as the non-destructive testing data of the cable. If there is no non-destructive testing data of the cable and other data that can express the health status of the cable, the value of each element of the vector d _o is 0.

d. While establishing the initial health state vector d _o , directly measure and calculate the initial values of all the monitored quantities of the cable structure, and form the initial value vector C _o of the monitored quantities;

e. While establishing the initial health state vector d _o and the initial value vector C _o of the monitored quantity, directly measure and calculate the initial cable force of all supporting cables to form the initial cable force vector F _o ; at the same time, according to the structural design data, The initial free lengths of all supporting cables are obtained from the as-built data to form the initial free length vector l _o ; at the same time, the initial geometric data of the cable structure are obtained according to the structural design data, as-built data or actual measurement; at the same time, all the The elastic modulus, density, and initial cross-sectional area of the cable;

f. Establish the mechanical calculation benchmark model A _o of the cable structure according to the design drawing of the cable structure, the as-built drawing, the measured data of the cable structure, the non-destructive testing data of the cable and the coordinate data of the initial support of the cable structure;

g. Carry out several mechanical calculations on the basis of the mechanical calculation benchmark model _Ao , and obtain the unit change matrix ΔC of the monitored quantity of the cable structure through calculation;

h. The current cable forces of all the supporting cables of the cable structure are measured to form the current cable force vector F; at the same time, the current measured values of all the specified monitored quantities of the cable structure are obtained through actual measurement to form the "current value vector C of the monitored quantities" ; 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;

i. Define the current health state vector d _c of the evaluated object and the current actual health state vector d; the number of elements of the vector d _o , d _c and d is equal to the number of evaluated objects, and the number of elements of d _o , d _c and d There is a one-to-one correspondence between the elements and the evaluated object, and the element values of d _o , d _c and d represent the damage degree or displacement of the corresponding evaluated object, or the damage degree mechanically equivalent to the degree of relaxation;

j. According to the difference between "the current numerical vector C of the monitored quantity" and "the initial numerical vector C _o of the monitored quantity", "the unit change matrix of the monitored quantity of the cable structure ΔC" and "the current health state vector d _c of the evaluated object" Existing approximate linear relationship, the approximate linear relationship can be expressed as formula 1, the other quantities in formula 1 except d _c are known, and the current health state vector d _c of the evaluated object can be calculated by solving formula 1;

C＝C _o +ΔC·d _c Formula 1

k. Using the relationship between the element d _j of the current actual health state vector d expressed in formula 2 and the element d _oj of the initial health state vector d _o and the element d _cj of the current health state vector d _c of the evaluated object, the current actual All elements of the health state vector d.

d _i ＝1-(1-d _oi )(1-d _ci ) Formula 2

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

Since the element value of the current actual health state vector d represents the current actual health state of the corresponding evaluated object, if the evaluated object is a cable in the cable system, then this element represents its current actual damage, if the evaluated object is A displacement component of a support, then this element represents its current displacement value; when the element value of the current actual health state vector d is 0, it means that the corresponding support cable has no damage and no relaxation, or the corresponding support displacement component is 0, The elements that are not 0 correspond to the problematic support cable or the support with displacement; thus the problematic support cable is determined and the support displacement is determined;

l. From the problematic support cables identified in the k step, the damaged cables are identified by non-destructive testing methods, and the rest are slack cables;

m. Take out the corresponding elements of the support cable from the current actual health state vector d to form the current actual health state vector d ^c of the support cable. The current actual health state vector d ^c of the support cable has Q elements, indicating the current actual damage of Q root support cables value, the numbering rule of d ^c elements is the same as that of vector F _o , that is, elements with the same number of d ^c and F _o represent the information of the same support cable;

n. Use the current actual health state vector d ^c of the supporting cables obtained in the mth step to obtain the current actual damage degree of the slack cables, use the current cable force vector F obtained in the hth step, and use all the supporting cables obtained in the hth step The spatial coordinates of the two supporting end points of , using the initial free length vector l _o obtained in step e, using the elastic modulus, density, and initial cross-sectional area data of all cables obtained in step e, by combining the relaxed 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 damage degree. The equivalent mechanical conditions are: the initial free length of the two equivalent cables without relaxation and damage, The 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 slack cables and damaged cables are the same; when the above two equivalent conditions are met, 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; It is judged as the slack degree of the slack cable, which is the change of the free length of the support cable, that is, the adjustment amount of the cable length of the support cable whose force needs to be adjusted is determined; in this way, the slack identification of the support cable is realized; when calculating The required cable force is given by the corresponding element of the current cable force vector F;

In step g, several mechanical calculations are performed on the basis of the mechanical calculation benchmark model A _o , and the specific method for obtaining the unit change matrix ΔC of the monitored quantity of the cable structure through calculation is as follows:

g1. Carry out several mechanical calculations on the basis of the mechanical calculation benchmark model A _o of the cable structure, and the number of calculations is numerically equal to N; each calculation assumes that only one assessed object has a unit damage or unit damage on the basis of the original healthy state. Displacement, for the convenience of description, this invention collectively refers to unit damage and unit displacement as unit change; specifically, if the object to be evaluated is a support cable in the cable system, then it is assumed that the support cable is rebuilt on the basis of the original healthy state. Increase the 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 on the basis of the original healthy state in the displacement direction, and use Du _ui to record the unit damage or unit displacement, where i represents the number of the evaluated object with unit damage or unit displacement; the evaluated object with unit damage or unit displacement in each calculation is different from the evaluated object with unit damage or unit displacement in other calculations , each calculation uses the mechanical method to calculate the current calculation values of all the monitored quantities of the cable structure, and the current calculation values of all the monitored quantities obtained by each calculation form a current vector for the calculation of the monitored quantities;

g2. The current vector of the monitored quantity calculated by each calculation minus the initial 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 evaluated The object has N monitored quantity change vectors;

g3. A cable structure monitored quantity unit change matrix ΔC with N columns is sequentially composed of the N monitored quantity change vectors; each column of the cable structure monitored quantity unit change matrix ΔC corresponds to a monitored quantity change vector.

Beneficial effects: the system and method disclosed in the present invention can very accurately monitor and evaluate the health state of the cable structure (including all bearing displacement, location of all slack and damaged cables, and their degree of slack or damage). The systems and methods disclosed in the present invention are highly beneficial for effective health monitoring of cable structures.

Detailed ways

The invention discloses a system and a method capable of reasonably and effectively monitoring the support displacement of a cable structure and identifying damaged and slack cables. 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 i One number, i=1, 2, 3, . . . , N.

Determine the supporting cables that will be monitored for the cable force specified during mixed monitoring. Suppose there are Q cables in the cable system, and the monitored cable force data of the structure is described by M ₁ cable force data of M ₁ specified cables on the structure. The change in structural cable force is the change in cable force for all specified cables. Each time there are _M1 cable force measurements or calculations to represent the cable force information of the structure. M ₁ is an integer not less than 0. When actually selecting the cables whose cable forces are to be monitored, those cables whose cable forces are easy to measure can be selected as the cables to be monitored.

Determine the measured points to be monitored for the specified strain during mixed monitoring. The monitored strain data of the structure can be described by the strains of K ₂ designated points on the structure and L ₂ designated directions of each designated point. The structural strain The change of the data is the change of all the measured strains of _K2 specified points. Each time there are M ₂ strain measurements or calculations to characterize the structural strain, and M ₂ is the product of K ₂ and L ₂ . M ₂ is an integer not less than 0. Each measured point to be monitored for strain can be a point near the fixed end of each cable (for example, the fixed end of the cable of a cable-stayed bridge on the bridge), and the designated point can also be near the structural support Generally, this point should not be a stress concentration point to avoid excessive strain measurement values, and these points should generally not all be the fixed end points of the cable force to be monitored during mixed monitoring or near it .

Determine the measured point to be monitored for the specified angle during mixed monitoring. The monitored angle data of the structure consists of K ₃ designated points on the structure, L ₃ designated straight lines passing through each designated point, and each designated straight line H is described by _three angle coordinate components, and the change of the structure angle is the change of all specified points, all specified lines, and all specified angle coordinate components. Each time there are M ₃ measured or calculated values of angular coordinate components to represent the angular information of the structure, and M ₃ is the product of K ₃ , L ₃ and H ₃ . M ₃ is an integer not less than 0. Each designated point can be the fixed end point of each cable (for example, the fixed end of the stay cable of a cable-stayed bridge on the bridge surface) or a point near it, and the designated point can also be a point near the structural support , the points of the monitored angle data should generally not all be selected as "the fixed end point of the cable force to be monitored in the mixed monitoring or a point near it" and "the point of the strain to be monitored in the mixed monitoring or at Nearby points"; at each specified point, only one angular coordinate of a specified straight line can be measured, for example, the angular coordinate of the surface normal or tangent of the structure that has passed the specified point relative to the direction of gravitational acceleration is measured, which is actually the measurement of inclination.

The shape data to be monitored specified when determining the mixed monitoring, the monitored shape data of the structure is described by the spatial coordinates of K ₄ designated points on the structure and L ₄ designated directions of each designated point, the structural shape data The change of is the change of all coordinate components of K ₄ designated points. Each time there are M ₄ coordinate measurements or calculations to characterize the shape of the structure, and M ₄ is the product of K ₄ and L ₄ . M ₄ is an integer not less than 0. Each designated point can be the fixed end point of each cable (for example, the fixed end of the stay cable of a cable-stayed bridge on the bridge), and the designated point can also be a point near the structural support, or directly the structural support The fulcrum; the selected points to be monitored here should not all be "the fixed end point of the cable force to be monitored specified in the hybrid monitoring or a point near it", "the point to be monitored strain specified in the hybrid monitoring or at its Nearby points" and "Points of the monitored angle data specified in the mixed monitoring or points near it".

Based on the above-mentioned monitored quantities, the entire structure has M monitored quantities in terms of mixed monitoring, M is the sum of M ₁ , M ₂ , M ₃ and M ₄ , and the parameter K is defined, and K is M ₁ , K ₂ , K ₃ The sum of K and ₄ , K and M must not be less than the number N of objects being evaluated. For the sake of convenience, in the present invention, the "all monitored parameters of the structure during mixing monitoring" listed in this step are referred to as "monitored quantities" for short.

The second step: use the non-destructive testing data of the cable and other data that can express the health state of the cable to establish the initial health state vector d _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 of the vector d _o is 0.

Step 3: While establishing the initial health state vector d _o , directly measure and calculate the initial values of all monitored quantities of the cable structure to form the "initial value vector C _o of the monitored quantities"; at the same time, directly measure and calculate the index The initial cable forces of all supporting cables of the structure constitute 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 completion data, and form the "initial free length vector l _o "; meanwhile, the measured Or obtain the elastic modulus, density, and initial cross-sectional area of all cables according to the structural design and completion data.

Step 4: While establishing the initial health state vector d _o , mature measurement methods can be used for cable force measurement, strain measurement, angle measurement and space coordinate measurement. The initial geometric shape data of the cable structure (for cable-stayed bridges, its initial bridge type data) can be obtained by direct measurement or calculated after measurement. The initial geometric shape data of the cable structure can be the spatial coordinate data of the end points of all cables plus a series of structural The spatial coordinate data of points is used 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 actual measurement data of the cable structure when the cable structure is completed, the actual measurement data includes the shape data of the cable structure, the data of the cable force, the data of the pulling force of the tie rod, the coordinate data of the support of the cable structure, the modal data of the cable structure, the elastic modulus of all cables, Density, initial cross-sectional area and other measured data, cable non-destructive testing data and other data that can express the health state of the cable, according to the design drawing and as-built drawing, use the mechanical method to establish the initial mechanical calculation benchmark model A _o of the cable structure; if there is no cable The actual measurement data of the structure when the structure is completed, then the actual measurement of the cable structure is carried out before the establishment of the health monitoring system, and the actual measurement data of the cable structure is also obtained. According to this data and the design drawing and completion drawing of the cable structure, the mechanical method is also used Establish the initial mechanical calculation benchmark model A _o of the cable structure; no matter what method is used to obtain A _o , the calculated data of the cable structure based on A _o must be very close to the measured data, and the difference between them must not be greater than 5%; A _o is not change; the health state of the cable structure corresponding to A _o is described by d _o ;

Step 5: Install the hardware part of the cable structure health monitoring system. The hardware part includes at least: the monitored quantity monitoring system (such as angle measurement subsystem, cable force measurement subsystem, strain measurement subsystem, space coordinate measurement subsystem, signal conditioner, etc.), cable force monitoring system (such as acceleration sensor , signal conditioner, etc.), the horizontal distance monitoring system of the two supporting ends of each supporting cable (such as measuring with a total station), signal (data) collector, computer and communication alarm equipment. Each monitored quantity, the cable force of each supporting cable and the horizontal distance between the two supporting ends of each supporting cable must be monitored by the monitoring system, and the monitoring system will transmit the monitored signal to the signal (data) collector; the signal It is transmitted to the computer through the signal collector; the computer is responsible for running the health monitoring software of the cable system of the cable structure, including recording the signal transmitted by the signal collector; Personnel, owners and (or) designated personnel call the police.

Step 6: Compile and install the health monitoring system software for running the cable structure on the monitoring computer. This software will complete the monitoring, recording, control, storage, calculation, notification, alarm and other functions required by the task of "a cable structure health monitoring method based on hybrid monitoring" of the present invention (that is, all of the specific implementation methods can be completed by computer. work), and can periodically or by personnel operate the health monitoring system to generate a report on the health of the cable structure, and can also automatically notify or prompt the monitoring personnel to notify specific technical personnel to complete the necessary computing work.

Step 7: Carry out several mechanical calculations on the basis of the mechanical calculation benchmark model A _o , and obtain the unit change matrix ΔC of the monitored quantity of the cable structure through calculation; the specific method is: on the basis of the mechanical calculation benchmark model A _o of the cable structure Carry out several mechanical calculations, and the number of calculations is numerically equal to N; each calculation assumes that only one evaluated object has unit damage or unit displacement on the basis of the original health state (expressed by the initial health state vector d _o of the cable structure), as For the convenience of description, the present invention collectively refers to unit damage and unit displacement as unit change. Specifically, if the object to be evaluated is a support cable in the cable system, then it is assumed that the support cable increases the unit damage on the basis of the original healthy state. , if the evaluated object is the displacement component of a bearing in one direction, it is assumed that the bearing will increase the unit displacement on the basis of the original healthy state in the displacement direction, and use Du _ui to record this unit damage or unit displacement , where i represents the number of the evaluated object with unit damage or unit displacement; the evaluated object with unit damage or unit displacement in each calculation is different from the evaluated object with unit damage or unit displacement in other calculations, each time Calculation uses the mechanical method to calculate the current calculation value of all the monitored quantities of the cable structure, and the current calculation values of all the monitored quantities obtained by each calculation form a monitored quantity calculation current vector (when it is assumed that the i-th monitored quantity has a unit In case of damage or unit displacement, it can be expressed by the current vector C _t ⁱ calculated by the monitored quantity); the calculated current vector of the monitored quantity obtained by each calculation minus the initial vector of the monitored quantity is divided by the assumed unit damage or Unit displacement value, get a monitored variable change vector, there are N monitored variable change vectors if there are N evaluated objects; the N monitored variable change vectors are formed in turn with N columns of cable structure. The monitored variable unit changes Matrix ΔC; each column of cable structure monitored quantity unit change matrix ΔC corresponds to a monitored quantity change vector. 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 has the same numbering as in other vectors. Elements express the relevant information of the same monitored quantity or the same evaluated object.

Step 8: Establish linear relationship error vector e and vector g. Using the previous data ("the initial value vector C _o of the monitored quantity", "the unit change matrix of the monitored quantity of the cable structure ΔC"), while performing each calculation in the seventh step, that is, each calculation assumes that there is only one On the basis of the original state of health d _o , the evaluation object adds unit damage or unit displacement, and calculates a monitored quantity to calculate the current vector (when it is assumed that the i-th monitored quantity has unit damage or unit displacement, the monitored quantity is used to calculate At the same time as the current vector C _t ⁱ represents), each calculation forms a "health state vector d _t ", the number of elements of the health state vector d _t is equal to the number of evaluated objects, and there is only one among all elements of the health state vector d _t The value of the element is the unit change value of the evaluated object that is assumed to increase the unit change in each calculation, and the value of other elements of d _t is 0; the numbering rules of C _t ⁱ , C _o , d _t are the same as the row of ΔC The numbering rules are the same; put C _t ⁱ , C _o , ΔC, and d _t into formula (13) (it should be noted that in formula (13), C is brought in by C _t ⁱ , and d _c is brought in by d _t ), A linear relationship error vector e is obtained, and a linear relationship error vector e is obtained for each calculation; if there are N evaluated objects, there are N calculations, and there are N linear relationship error vectors e, and these N linear relationship error vectors e A vector is obtained after addition, and the new vector obtained by dividing each element of this vector by N is the final linear relationship error vector e. The vector g is equal to the final error vector e. Save the vector g on the computer hard disk running the health monitoring system software for use by the health monitoring system software.

Step 9: Combine "initial cable force vector F _o ", "initial value vector C _o of the monitored quantity", "initial free length vector l _o ", "monitored quantity unit change matrix ΔC of the cable structure" and all cables Parameters such as elastic modulus, initial cross-sectional area, and weight per unit length of the cable are stored in the form of data files on the hard disk of the computer running the health monitoring system software.

Step 10: Obtain the current cable force of all the supporting cables of the cable structure through actual measurement to form the current cable force vector F; at the same time, obtain the current measured values of all specified monitored quantities of the cable structure through actual measurement to form the "current value vector of the monitored quantity C". 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: According to "the current (calculated or measured) numerical vector C of the monitored quantity" and "the initial numerical vector C _o of the monitored quantity", "the cable structure monitored quantity unit change matrix ΔC" and "the evaluated object There is an approximate linear relationship between the current health state vector d _c ” (see formula (9)), and the non-inferior solution of the current health state vector d _c of the evaluated object of the cable system is calculated according to the multi-objective optimization algorithm.

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 (Constran Method), Weighted Sum Method, Goal Attanment Method, etc. Since various multi-objective optimization algorithms are conventional algorithms, they can be implemented conveniently. This implementation step only uses the goal programming method as an example to give the process of solving the current health state vector d _c of the evaluated object. The specific implementation process of other algorithms can be based on The requirements of its specific algorithm 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 (26) and Equation (27). In Equation (26), γ is a real number, R is the field of real numbers, and the space region Ω limits the vector The value range of each element of d _c (this embodiment requires that each element of the vector d _c corresponding to the support cable is not less than 0 and not greater than 1; each element corresponding to the displacement of the support is selected according to the constraint range of the support , for example, the bridge tower support placed on the bridge pier should not have a displacement greater than 2 meters). Equation (26) means to find a real number γ with the smallest absolute value, so that Equation (27) is satisfied. G(d _c ) in formula (27) is defined by formula (28), and the product of weighted vector W and γ in formula (27) represents the allowable deviation between G(d _c ) and vector g in formula (27), g Refer to formula (15) for the definition of , and its value is calculated in the eighth step. The vector W may be the same as the vector g during 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 damage vector d _c can be obtained.

minimize ¶

(26)

γ ∈ R, d _c ∈ Ω

G(d _c )-Wγ≤g (27)

G(d _c )=abs(ΔC·d _c -C+C _o ) (28)

After the current health state vector d _c of the evaluated object is obtained, each element of the current actual health state vector d can be obtained according to formula (17). The current actual health state vector d has reasonable errors, but can accurately identify The cable of the problem (which may be damaged or loose) can determine the solution of all support displacements with relative accuracy. If each element of the solved current actual health state vector d corresponds to the health state of an evaluated object, if the evaluated object is a cable (or tie rod) in the cable system, then the value of this element represents its current Damage or relaxation, if the object being evaluated is a displacement component of a bearing, then the value of this element represents its current displacement value.

Step Twelve: Identify damaged and slack cords. Since the element value of the current actual health state vector d represents the current actual health state of the corresponding evaluated object, if an element d _i of d corresponds to a cable (or tie rod) in the cable system, then d _i represents its current possible Actual damage, 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, but whether the cable has been damaged Slack still occurs, 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 not 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 ( That is, the cable length adjustment). This enables damaged and slack cable identification.

Step 13: Identify the bearing displacement. The element value corresponding to the support displacement of the current actual health state vector d is the support displacement.

Step 14: 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.

Step 15: 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.

Claims (2)

1. cable structure health monitoring method based on hybrid 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 i, i=1,2,3 ..., N;

The support cable with monitored Suo Li of appointment when b. determining hybrid monitoring is established total Q root support cable in the cable system, and the monitored rope force data of structure is by M on the structure ₁The M of individual appointment support cable ₁Individual rope force data is described, and the variation of structure Suo Li is exactly all variations of specifying the Suo Li of support cable; Each total M ₁Individual cable force measurement value or calculated value characterize the rope force information of structure; M ₁Be one and be not less than 0 integer; The measured point with monitored strain of appointment when determining hybrid monitoring, the monitored strain data of structure is by K on the structure ₂L individual specified point, that reach each specified point ₂The strain of individual assigned direction is described, and the variation of structural strain data is exactly K ₂The variation of the tested strain of all of individual specified point; Each total M ₂Individual strain measurement value or calculated value characterize structural strain, M ₂Be K ₂And L ₂Long-pending; M ₂Be to be not less than 0 integer; The measured point with monitored angle of appointment when determining hybrid monitoring, the monitored angle-data of structure is by K on the structure ₃L individual specified point, that cross each specified point ₃H individual appointment straight line, each appointment straight line ₃Individual angle coordinate component is described, and the variation of structure angle is exactly variations all specified points, all appointments angle coordinate components straight line, all appointments; Each total M ₃Individual angle coordinate component measurement value or calculated value characterize the angle information of structure, M ₃Be K ₃, L ₃And H ₃Long-pending; M ₃Be one and be not less than 0 integer; When determining hybrid monitoring appointment with monitored shape data, the monitored shape data of structure is by K on the structure ₄L individual specified point, that reach each specified point ₄The volume coordinate of individual assigned direction is described, and the variation of planform data is exactly K ₄The variation of all coordinate components of individual specified point; Each total M ₄Individual measurement of coordinates value or calculated value characterize planform, M ₄Be K ₄And L ₄Long-pending; M ₄Be one and be not less than 0 integer; The monitored amount of comprehensive above-mentioned hybrid monitoring, total M the monitored amount of total, M is M ₁, M ₂, M ₃And M ₄Sum, definition parameter K, K is M ₁, K ₂, K ₃And K ₄Sum, K and M must not be less than the quantity N of evaluation object; Because M monitored amount is dissimilar, " all monitored parameters of structure during hybrid monitoring " that this step is listed abbreviate " monitored amount " as;

C. the data of utilizing the Non-Destructive Testing data of support cable can express the health status of support cable are set up initial health vector d _oIf when not having the data of the Non-Destructive Testing data of support cable and other health status that can express support cable, vectorial d _oEach element numerical value get 0;

D. setting up initial health vector d _oThe time, directly measurement calculates the initial value of all monitored amounts of Cable Structure, forms the initial value vector C of monitored amount _o

E. setting up initial health vector d _oInitial value vector C with monitored amount _oThe time, 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 _oSimultaneously, obtain the initial geometric data of Cable Structure according to structural design data, completion data or actual measurement; Simultaneously, survey or obtain elastic modulus, density, the initial cross sectional area of all support cables according to structural design, completion information;

F. according to the measured data of design drawing, as-constructed drawing and the Cable Structure of Cable Structure, the Non-Destructive Testing data of support cable and the Mechanics Calculation benchmark model A that initial Cable Structure support coordinate data are set up Cable Structure _o

G. at Mechanics Calculation benchmark model A _oThe basis on carry out the several times Mechanics Calculation, by calculate obtaining the monitored amount unit change of Cable Structure matrix Δ C;

H. actual measurement obtains the current cable power of all support cables of Cable Structure, forms current cable force vector F; Simultaneously, actual measurement obtain Cable Structure all specify the current measured value of monitored amount, form " the current numerical value vector C of monitored amount "; Actual 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;

I. define the current health status vector of evaluation object to be asked d _cWith current actual health status vector d; Vector d _o, d _cEqual the quantity of evaluation object, d with the element number of d _o, d _cAnd be one-to-one relationship between the element of d and the evaluation object, d _o, d _cWith the element numerical value of d represent the degree of injury of corresponding evaluation object or displacement or with the degree of injury of relax level mechanics equivalence;

J. according to " the current numerical value vector C of monitored amount " " the vectorial C of the initial value of monitored amount together _o", " the monitored amount unit change of Cable Structure matrix Δ C " and " the current health status of evaluation object vector d _c" between the linear approximate relationship that exists, this linear approximate relationship is expressed as formula 1, removes d in the formula 1 _cOther outer amount is known, finds the solution formula 1 and just can calculate the current health status vector of evaluation object d _c

C=C _o+ Δ Cd _cFormula 1

K. utilize the element d of the current actual health status vector d of formula 2 expression _iWith initial health vector d _oElement d _OiWith the current health status vector of evaluation object d _cElement d _CiBetween relation, calculate all elements of current actual health status vector d;

d _i=1-(1-d _Oi) (1-d _Ci) formula 2

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

Because the element numerical value of current actual health status vector d is represented the current actual health status of corresponding evaluation object, if this evaluation object is a support cable in the cable system, its current actual damage of this element representation so, if this evaluation object is a displacement component of a bearing, its present bit shift value of this element representation so; The element numerical value of current actual health status vector d is 0 o'clock, and it is 0 that the corresponding support cable not damaged of expression does not have lax or corresponding support displacement component, is not 0 element corresponding to problematic support cable or the bearing of displacement is arranged; Determine problematic support cable thus, determined support displacement;

L. from the problematic support cable that k identified the step, identify damaged cable by lossless detection method, remaining is exactly slack line;

M. from current actual health status vector d, take out the element of support cable correspondence and form the current actual health status vector d of support cable ^c, the current actual health status vector d of support cable ^cQ element arranged, the current actual damage value of expression Q root support cable, d ^cThe coding rule of element and vectorial F _oCoding rule identical, i.e. d ^cAnd F _oThe information of the element representation same support rope of identical numbering;

N. utilize the current actual health status vector d of the support cable that obtains in the m step ^cObtain the current actual damage degree of slack line, utilize the current cable force vector F that obtains in the h step, utilize the volume coordinate of two supporting end points of all support cables that obtain in the h step, utilize the initial drift vector l that obtains in the e step _oUtilization is in elastic modulus, density, the initial cross sectional area data of all support cables of e step acquisition, by with slack line with damaged cable carry out the mechanics equivalence calculate slack line, with the relax level of current actual damage degree equivalence, the mechanics equivalent condition 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 support cable 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 provided by current cable force vector F corresponding element during calculating.

2. a kind of cable structure health monitoring method based on hybrid monitoring according to claim 1 is characterized in that in step g, at Mechanics Calculation benchmark model A _oThe basis on carry out the several times Mechanics Calculation, by the concrete grammar that calculate to obtain the monitored amount unit change of Cable Structure matrix Δ C be:

G1. at the Mechanics Calculation benchmark model A of Cable Structure _oThe basis on carry out the several times Mechanics Calculation, equal N on the calculation times numerical value; Calculate hypothesis each time and have only an evaluation object to increase on the basis of former health status unit damage or unit displacement are arranged again, this method is collectively referred to as unit damage and unit displacement is a unit change for sake of convenience; Concrete, if this evaluation object is a support cable in the cable system, so just suppose that this support cable increases unit damage again on the basis of original health status, if this evaluation object is the displacement component of a direction of a bearing, just suppose that this bearing increases the generation unit displacement again on the basis of this sense of displacement in original health status, use D _UiWrite down this unit damage or unit displacement, wherein i represents to take place the numbering of the evaluation object of unit damage or unit displacement; The evaluation object that occurs unit damage or unit displacement in calculating each time is different from the evaluation object that occurs unit damage or unit displacement in other time calculating, calculate the current calculated value that all utilizes mechanics method to calculate all monitored amounts of Cable Structure each time, the current calculated value of the monitored amount of all that calculate is formed a monitored amount calculation current vector each time;

G2. the monitored amount calculation current vector that calculates is each time calculated unit damage or the unit displacement numerical value of being supposed divided by this time after deducting monitored amount initial vector again, obtain a monitored quantitative change vector, have N evaluation object that N monitored quantitative change vector just arranged;

G3. form the monitored amount unit change of the Cable Structure matrix Δ C that the N row are arranged successively by this N monitored quantitative change vector; Each row of the monitored amount unit change of Cable Structure matrix Δ C are corresponding to a monitored quantitative change vector.