KR102145449B1 - Apparatus and Method for Monitoring Damage of Structure with Measuring Strain and Digital Twin - Google Patents

Abstract

In order to monitor structural stability and damage of structures such as bridges, the present invention installs a strain measurement device capable of measuring strain at a plurality of measurement points on a target structure, and uses the initial strain measured at a plurality of measurement points. , A hypothetical structural analysis model that shows the response characteristics of the target structure when a load is applied to the target structure, that is, the structural behavior and structural response of the structure identical to that of the target structure when a load is applied (digital twin). ) Is formed, the strain is measured at a desired time interval for a desired time through a strain measurement device, and applied to a virtual structural analysis model that has been built in advance, thereby determining and monitoring the damage of the target structure. It relates to a "damage monitoring method" and a "damage monitoring device of a structure" operated by this monitoring method.

Description

A method and apparatus for monitoring damage of a structure using strain measurement and a structural analysis model based on it {Apparatus and Method for Monitoring Damage of Structure with Measuring Strain and Digital Twin}

The present invention relates to a method and an apparatus for monitoring the damage of a structure using a strain measurement and a structural analysis model based thereon. Specifically, a plurality of structures (target structures) to be monitored for structural stability and damage A strain measurement device that can measure the strain at three measurement points is installed, and using the initial strain measured at a plurality of measurement points, it shows the same response characteristics as the response characteristics of the target structure when a load is applied. , After forming a virtual structural analysis model (digital twin) that shows the structural behavior and structural response of the structure identical to that of the target structure when a load is applied, the strain rate at a desired time interval for a desired time through a strain measurement device By measuring and applying it to a virtual structural analysis model built in advance, the "Structure Damage Monitoring Method" that determines and monitors the damage of the target structure and the "Structure Damage Monitoring Device" operated by this monitoring method. "It's about.

It is very important to monitor in advance whether any damage has occurred to structures such as bridges. If the damage to the structure is not identified in the early stage of occurrence, the damaged area gradually spreads, and if it is repaired and reinforced later, it is costly because a wider and deeper damaged area must be repaired. In addition, fundamentally, damage to the structure is a factor that directly affects the safety of the structure, so measures must be taken early in the occurrence. Therefore, monitoring the structure so that it can accurately recognize the damage in advance is very important and necessary in the maintenance of the structure.

In monitoring whether damage has occurred in structures such as bridges, a method of monitoring using a mathematical analysis model has been proposed. That is, a structural analysis model based on the finite element analysis method is set for the target structure to be monitored, and the state of the target structure, that is, whether or not damage has occurred, is determined using the structure analysis model. However, the structural analysis model used in the prior art is based on an acceleration measurement value measured from a target structure. Therefore, in order to monitor the occurrence of damage to the target structure using the structural analysis model of the prior art, a small number of accelerometers are installed on the target structure and the accelerometer measures and acquires the acceleration value at the measurement point, and the measured acceleration value is used. The structural analysis model should be set in such a way that the natural frequency and the natural mode shape of the target structure are obtained, and the stiffness and boundary conditions of the target structure in the structural analysis model are matched with the natural frequency and the natural mode shape of the target structure obtained by measurement. do.

However, the natural frequency and the natural mode shape of the structure used in the prior art as described above has the property that it hardly changes due to local damage such as concrete cracking. Even if a cable break accident that can cause collapse occurs in the cable-stayed bridge, the change in the natural frequency and the shape of the natural mode of the cable-stayed bridge is insignificant, and a serious accident such as a cable break cannot be detected. Therefore, the natural frequency and the natural mode shape of the structure calculated from the measured acceleration value do not reflect the local damage of the structure, and are insensitive to accidents that have a great influence on the overall behavior of the structure, and do not properly reflect the current state of the structure. It has the disadvantage of not being able to. In the end, in the case of the prior art using the structural analysis model constructed based on the natural frequency and the natural mode shape, which is insensitive to changes in the structural state, the damage state of the structure is not properly understood, and in the end, there is a limitation in that the proper repair and reinforcement time is missed .

On the other hand, when local damage occurs to the structure, it immediately appears as an increase in strain. Also, when a large change occurs in the structure, the deflection shape of the structure changes, which in turn leads to a change in the strain rate. Therefore, the strain of a structure becomes an important measure that can detect local damage and change in overall behavior of the structure, unlike acceleration. By constructing a structural analysis model based on the strain rate with such advantages, the degree of damage to the structure can be accurately modeled, thereby enabling proper repair and reinforcement.

In this way, since the strain reflects the damage characteristics of the structure, it is desirable to determine and monitor the occurrence of damage to the target structure based on this strain, but for this purpose, not only reliable measurement of the strain, but also enough to be used in a structural analysis model. It should be possible to measure the strain at many measurement points. In the past, the strain was measured only at a few measurement points, but in recent years, through the development of measurement technology, it is possible to accurately measure the strain of a structure at a sufficient number of measurement points to be used in a structural analysis model, such as a Brillouin fiber strain sensor. Technology is being developed.

However, since the strain measurement technology is also recently developed, the strain measurement values obtained from a number of measurement points can be efficiently used for structural analysis or monitoring of structures based on structural analysis models. The development of technology is very insufficient.

Korean Patent Application Publication No. 10-2012-0029061 (published on March 26, 2012).

The present invention was developed to overcome the limitations of the prior art as described above and to utilize the results of the recently developed measurement technology, and the structural response that appears in the structure when a load is loaded, that is, the structural response of the structure to the load Based on the strain that can sensitively reflect the behavior and structural response, a structural analysis model is built for the structure, and the structural analysis model and the measurement strain are used to provide a technology to monitor the occurrence of damage to the structure. It is aimed at.

In the present invention, in the present invention, a strain measurement device capable of measuring strain at a plurality of measurement points is disposed on a structure to be monitored for damage occurrence, and an initial load of a known base is loaded on the target structure and a strain measurement device is used. Measuring the initial strain; The measured initial strain is transmitted to a computing device comprising a signal receiver, a strain-strain conversion unit, a stiffness matrix derivation unit, and a structure damage determination unit, and the initial strain is calculated by the strain-strain conversion unit of the computing device. Converting and calculating the initial transformation; Deriving an initial stiffness matrix representing a response characteristic to a load of a target structure through calculation in a stiffness matrix derivation unit provided in the computing device; Measuring a strain in a state of use when a known working load is loaded on the target structure at a time determined by the administrator using a strain measuring device installed in the target structure; The measured usage state strain is transmitted to a computing device, and the strain-deformation conversion unit of the computing device converts the measured usage state strain into a usage state strain to calculate a usage state strain; And determining whether the target structure is damaged by using the used load, the calculated deformation of the used state, and the initial stiffness matrix derived as a structural analysis model for the target structure, in the structure damage determination unit of the computing device. And, by using a strain measurement and a structural analysis model based thereon, a method for monitoring and determining whether structural damage has occurred in a target structure is provided.

In addition, in the present invention, in order to achieve the above object, the strain measurement device can measure the strain at a plurality of measurement points, and the strain measurement device disposed on the structure to be monitored for damage, and the signal from the strain measurement device are received to damage the target structure. And a computing device that performs an operation for monitoring whether or not, the computing device includes a signal receiving unit, a strain-strain conversion unit, a stiffness matrix derivation unit, and a structure damage determination unit; In the signal receiving unit, the initial strain measured by the strain measuring device is received when the target structure is loaded with a known initial load; In the strain-strain conversion unit, the received initial strain is converted into an initial strain and is calculated; In the stiffness matrix derivation unit, the initial stiffness matrix representing the response characteristics to the load of the target structure is calculated and derived; In the strain-strain conversion unit, the state of use when a known working load is loaded on the target structure at a time set by the administrator, when the strain is measured and transmitted by the strain measuring device installed in the target structure, the state of use measured through calculation Converting the strain rate into a state of use transformation to calculate the state of use transformation; In the structure damage determination unit, it is determined whether the target structure is damaged using the used load, the calculated state of use deformation, and the initial stiffness matrix derived as a structural analysis model for the target structure; A structural damage monitoring device is provided, characterized in that it monitors and determines whether structural damage has occurred in a target structure using strain measurement and a structural analysis model based thereon.

In the above-described apparatus and method for monitoring damage to a structure according to the present invention, when calculating by converting the initial strain into the initial strain in the strain-strain conversion unit, the process of dividing the target structure into the number of analysis elements determined by the administrator; For each of the divided analysis elements, a process of calculating and deriving a transformation matrix representing the relationship between the node deformation and the strain at the <strain rate measurement point existing in the analysis element; A process of calculating and deriving a transformation matrix for the entire target structure by integrating the derived transformation matrix of each analysis element; And calculating the initial deformation of the target structure by multiplying the derived transformation matrix for the entire target structure by the initial deformation rate.

In the present invention, a structural analysis model is constructed based on strain, which is an important measure capable of detecting local damage and overall behavior change of the structure by reflecting the damage characteristics of the structure, and in real time at a plurality of measurement points of the target structure. Using the measured strain measurement value and the set structural analysis model, the damage or not and the location of the structure is identified.

Therefore, according to the present invention, it is possible to preemptively prepare and prepare an appropriate method to cope with damage to the structure, and it is possible to maintain the structure more safely.

1 is a schematic flowchart of a detailed process of a method for monitoring damage to a structure according to the present invention.
FIG. 2 is a schematic configuration diagram of an apparatus of the present invention for monitoring whether a structure is damaged by the method of the present invention shown in FIG. 1.
3 is a schematic diagram showing a state in which a distributed optical fiber sensor is installed as a strain measurement device in a two-dimensional beam as an example of a target structure to which the present invention is applied.
4 is a schematic flowchart of a detailed process of a step of converting an initial strain to an initial strain performed in the present invention.
5 is a schematic diagram showing a case in which the two-dimensional beam illustrated in FIG. 3 is divided into four analysis elements in order to form a structural analysis model.
6 is a schematic diagram showing a case in which the two-dimensional beam illustrated in FIG. 3 is divided into eight analysis elements in order to form a structural analysis model.
7 is a schematic partial enlarged view showing only the first analysis element in an enlarged manner when the two-dimensional beam shown in FIG. 5 is used as a target structure and divided into four analysis elements.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention has been described with reference to the embodiment shown in the drawings, but this is described as an embodiment, by which the technical idea of the present invention and its core configuration and operation are not limited.

FIG. 1 is a schematic flowchart of a detailed process of the "method for monitoring whether a structure is damaged" according to the present invention, and FIG. 2 is a view for monitoring whether a structure is damaged by the method of the present invention shown in FIG. A schematic configuration diagram of the device of the invention is shown. In FIG. 2, the line indicated by the arrow K means that the measured value is transmitted from the strain measurement device.

The "damage monitoring device of a structure" according to the present invention includes a strain measurement device (for example, a distributed optical fiber sensor) 1 installed in a target structure 200 to monitor whether damage occurs, and the strain measurement device ( It is configured to include a calculation device 100 that receives a signal from 1) and performs an operation and a series of execution processes for monitoring whether damage to the target structure 200 has occurred, and the calculation device 100 includes a signal receiving unit ( 10), a strain-strain conversion unit 20, a stiffness matrix derivation unit 30, and a structure damage determination unit 40. In the present invention, the computing device 100 may be implemented as software running on a computer. Therefore, the signal receiver 10, the strain-strain conversion unit 20, the stiffness matrix derivation unit 30, and the structure damage determination unit 40 constituting the computing device are each of software for performing its own function. It can be implemented as a module.

3 is a schematic diagram showing a state in which a distributed optical fiber sensor is installed as a strain measurement device 1 on a two-dimensional beam as an example of the target structure 200.

을 재하하고 변형률 계측 장치를 이용하여 변형률 즉, 초기 변형률(strain)

을 계측한다(단계 S1). 변형률 계측 장치(1)는 복수개의 변형률 계측점을 가지고 있으므로, 초기 하중을 재하함에 따라 측정되는 초기 변형률은, 계측점의 갯수에 해당하는 복수개의 계측값으로 이루어진 벡터로 표현된다. 즉, 초기 변형률

은, 변형률 계측 장치의 계측점 각각 에서 계측된 변형률

를 성분으로 가지는 벡터로 표현되며, 구체적으로,

형태가 된다. In order to monitor whether a structure is damaged according to the present invention, first, a strain measurement device 1 capable of measuring strain at a plurality of measurement points, such as a distributed optical fiber sensor, is installed on the target structure 200, and then the target structure Initial load known to (200)

Load and use a strain measuring device to determine the strain, that is, the initial strain

Is measured (step S1). Since the strain measurement device 1 has a plurality of strain measurement points, the initial strain measured by loading the initial load is expressed as a vector consisting of a plurality of measurement values corresponding to the number of measurement points. I.e. initial strain

Silver, strain measured at each measurement point of the strain measuring device

It is expressed as a vector having as a component, specifically,

It becomes a form.

은 연산장치(100)의 신호 수신부(10)로 전송되고, 연산장치(100)에 구비된 변형률-변형 변환 유닛(20)으로 전달되어, 변형률-변형 변환 유닛(20)에서의 연산을 통해서 초기 변형률

을 초기 변형(deformation)

으로 변환하여 산출한다(단계 S2). Measured initial strain

Is transmitted to the signal receiving unit 10 of the computing device 100, transferred to the strain-strain conversion unit 20 provided in the computing device 100, and is initially transmitted through the calculation in the strain-strain conversion unit 20. Strain

The initial transformation

And calculated (step S2).

4 is a schematic flowchart of a detailed process of a step of converting an initial strain to an initial strain performed in the present invention. In converting the strain into strain, a finite element analysis method can be used. Looking specifically, the target structure 200 is first divided into a number of analysis elements determined by the administrator (step S2-1). That is, the manager determines the number of analysis elements for applying the finite element analysis method to the target structure 200 and inputs it into the computing device 100, and accordingly, the strain-strain conversion unit 20 is applied in the finite element analysis method. It is to divide the target structure into the number of analysis elements determined by the administrator by a known method.

The smaller the number of analysis elements, that is, the larger the analysis elements, the more the measured strain in the analysis elements is averaged. Therefore, if you want to understand the effect of the strain on the deformation in detail, increase the number of analysis elements to reduce the element size, and if you want to understand the average deformation, reduce the number of analysis elements to increase the element size. 5 and 6 are schematic diagrams showing a case where the two-dimensional beam illustrated in FIG. 3 is divided into four analysis elements (Fig. 5) and eight analysis elements (Fig. 6), respectively. Is shown.

After the division into analysis elements is completed, in the strain-strain conversion unit 20, for each analysis element, a conversion matrix indicating the relationship between the <node deformation> and the <strain at the strain measurement point> existing in the analysis element An operation to derive is performed (step S2-2).

The relationship between the nodal deformation at each analysis element and the deformation at the strain measurement point may be basically expressed by Equation 1 below.

는, 대상 구조물에 대해 분할한 해석요소 중에서 하나의 해석요소의 "절점 변형"을 의미하며,

는 해당 해석요소에 내에 존재하는 변형률 계측점의 변형률 즉, "계측점의 변형률"을 의미하며,

는 해당 해석요소의 "변환행렬"을 의미한다. 대상 구조물은 유한요소해석을 위한 복수개의 해석요소로 분할된 상태이고 복수개의 절점과 복수개의 변형률 계측점을 가지고 있으므로, 위 수학식 1의 절점 변형

는 벡터로 표현되며, 계측점의 변형률

역시 벡터로 표현되며, 변환행렬

는 복수개의 행과 열을 가지는 행렬로 표현된다. In Equation 1 above

Means "node deformation" of one of the analysis elements divided for the target structure,

Means the strain of the strain measuring point that exists in the analysis element, that is, the "strain of the measuring point",

Means "transformation matrix" of the corresponding analysis element. Since the target structure is divided into a plurality of analysis elements for finite element analysis and has a plurality of nodes and a plurality of strain measurement points, the node deformation of Equation 1 above.

Is expressed as a vector, and the strain at the measurement point

It is also expressed as a vector, and the transformation matrix

Is expressed as a matrix having a plurality of rows and columns.

과

로 표시된 2개의 절점을 가지며, 각각의 절점에서는 수평 변형

와 수직 변형

, 그리고 회전 변형

이 발생하므로, 이 경우 수학식 1에서

로 표시된 해당 해석요소에서의 "절점 변형"은 아래의 수학식 2와 같이 표현될 수 있다. 도 7에서

와

는 각각 변형률 계측점의 좌표를 나타내며,

,

,

, ...는 각 변형률 계측점에서 계측된 초기 변형률 값을 나타낸다. In FIG. 7, when the two-dimensional beam shown in FIG. 5 is used as a target structure and divided into four analysis elements, only the first analysis element is enlarged. As shown in FIG. 7, the first analysis element is Alphabet letters from 5

and

It has two nodes marked with, and horizontal deformation at each node

And vertical transformation

, And rotation transformation

Since is generated, in this case, in Equation 1

The "node deformation" in the corresponding analysis element indicated by may be expressed as Equation 2 below. In Fig. 7

Wow

Represents the coordinates of each strain measurement point,

,

,

, ... represent the initial strain values measured at each strain measurement point.

는 다양한 공지의 제안식으로 표현할 수 있는데, 예를 들어 오일러-베르누이 빔(Euler-Bernoulli beam)에 대한 제안식을 이용하는 경우, 변환행렬

에서 좌표

,

의 변형률 계측점에 대한 변환행렬 값

는 아래의 수학식 3 및 수학식 4로 표현될 수 있다. Transformation matrix

Can be expressed as a variety of well-known proposed equations. For example, when using the proposed equation for Euler-Bernoulli beam, the transformation matrix

Coordinates from

,

Transformation matrix value for the strain measurement point of

May be expressed by Equation 3 and Equation 4 below.

,

및

은 각각 절점

에서의 수평 변형, 수직 변형, 및 회전 변형을 의미하며,

,

및

은 각각 절점

에서의 수평 변형, 수직 변형, 및 회전 변형을 의미한다. 그리고 수학식 4에서

은 해당 해석요소의 길이를 의미한다. In Equation 2 above

,

And

Each node

Means horizontal transformation, vertical transformation, and rotation transformation in,

,

And

Each node

Means horizontal deformation, vertical deformation, and rotational deformation. And in Equation 4

Means the length of the corresponding analysis element.

As shown above, the transformation matrix is expressed by a known proposed formula using the geometric shape of the analysis element and the coordinates of the strain measurement point.The manager who analyzes the value of the geometric shape of the analysis element and the coordinates of the strain measurement point Since the value is already known and input to the computing device 100, the strain-strain conversion unit 10 of the computing device 100 uses this known value for each strain measurement point in one analysis element. Through the operation, the value of the transformation matrix at each strain measurement point is calculated and expressed as a matrix to derive the "transformation matrix for the corresponding analysis element".

을 도출한다(단계 S2-3). 전체 대상 구조물에 대한 변환행렬

이 도출되면, 위의 수학식 1에 따라 아래의 수학식 5의 관계가 성립하게 된다. Since the target structure 200 is divided into a plurality of analysis elements, the strain-strain conversion unit 20 of the computing device 100 repeatedly performs the derivation of the conversion matrix for the analysis elements for each analysis element, By integrating the transformation matrix of each analysis element derived by this, the transformation matrix for the entire target structure

Is derived (step S2-3). Transformation matrix for all target structures

When is derived, the relationship of Equation 5 below is established according to Equation 1 above.

는 위에서 설명한 과정에 의해 전체 대상 구조물에 대해 도출해낸 변환행렬이고,

는 벡터로 표현된 초기 변형률(strain)이며,

는 벡터로 표현된 대상 구조물의 초기 변형(deformation)이다. In Equation 5 above,

Is the transformation matrix derived for the entire target structure by the process described above,

Is the initial strain expressed as a vector,

Is the initial deformation of the target structure expressed as a vector.

을 계측하여 취득한 상태이고, 위의 단계 S2-2를 통해서 대상 구조물의 변환행렬

을 도출하였으므로, 연산장치(100)의 변형률-변형 변환 유닛(10)에서는 수학식 5의 연산을 통해서, 대상 구조물의 초기 변형(deformation)

을 산출한다(단계 S2-4). 산출된 초기 변형

은, 앞서 언급한 것처럼 벡터로 표현된다. Initial strain through step S1

Is obtained by measuring, and the transformation matrix of the target structure through step S2-2 above

Since is derived, in the strain-deformation conversion unit 10 of the computing device 100, the initial deformation of the target structure through the calculation of Equation 5

Is calculated (step S2-4). Calculated initial transformation

Is expressed as a vector, as mentioned earlier.

을 변환하여 초기 변형

을 산출한 후에는, 연산장치(100)에 구비된 강성행렬 도출 유닛(30)에서는 연산을 통해서, 대상 구조물의 하중에 대한 응답특성을 나타내는 초기 강성행렬

을 도출한다(단계 S3). Thus, the measured initial strain

Transform the initial transformation

After calculating, the stiffness matrix derivation unit 30 provided in the computing device 100 uses an initial stiffness matrix representing the response characteristics to the load of the target structure through calculation.

Is derived (step S3).

와 대상 구조물에 가해진 초기 하중

는 아래의 수학식 6으로 표현되는 관계를 가진다. 여기서, 초기 하중은 벡터이므로, 편의상 영어 대문자를 사용하여

로 표현하였다. Initial deformation of the target structure

And the initial load applied to the target structure

Has a relationship expressed by Equation 6 below. Here, the initial load is a vector, so for convenience, English capital letters are used.

Expressed as.

는 초기 강성행렬로서, 이는 대상 구조물의 강성

와, 대상 구조물의 지지조건을 나타내는 스프링상수

의 함수이며, 초기 강성행렬의 수학적 함수 형태는 다양한 것이 이미 제안되어 공지되어 있다. 참고로 유한요소해석법에서는 대상 구조물이 지지되고 있는 지지조건을 스프링 상수로 표현할 수 있다. 벡터로 표현되는 초기 하중

는, 스칼라 값으로서 초기에 재하한 기지의 하중 값

와 하중 재하 위치로부터 공지의 기술을 통해 쉽게 구성할 수 있다. In Equation 6 above

Is the initial stiffness matrix, which is the stiffness of the target structure

Wow, spring constant indicating the supporting conditions of the target structure

It is a function of, and various types of mathematical functions of the initial stiffness matrix have already been proposed and known. For reference, in the finite element analysis method, the support condition in which the target structure is supported can be expressed as a spring constant. Initial load expressed as a vector

Is, as a scalar value, the known load value initially loaded

It can be easily constructed from the load-loading position and through known techniques.

은 미지의 상태이지만, 대상 구조물의 초기 변형

과 대상 구조물에 가해진 초기 하중

은, 변형률 계측 장치를 이용한 계측과 상기한 연산 과정을 통해서 도출되어 기지 상태의 것이다. 따라서, 강성행렬 도출 유닛(30)에서는, 관리자가 지정한 초기 강성행렬의 수학적 함수에 대해 최적화기법의 연산을 수행함으로써, 초기 강성행렬

을 도출하게 된다. Initial stiffness matrix for the target structure

Is unknown, but initial deformation of the target structure

And the initial load applied to the target structure

Is derived through measurement using a strain measurement device and the above-described calculation process, and is in a known state. Therefore, in the stiffness matrix derivation unit 30, the initial stiffness matrix is calculated by performing an optimization technique on the mathematical function of the initial stiffness matrix designated by the administrator.

Is derived.

의 값과 대상 구조물의 스프링상수

값을 변화시켜가면서 연산을 수행하여 수학식 7을 만족하게 되는 대상 구조물의 초기 강성 값

과 대상 구조물의 초기 스프링상수 값

를 찾아내는 것이며, 이렇게 찾아진 대상 구조물의 초기 강성 값

과 대상 구조물의 초기 스프링상수 값

에 의해 초기 강성행렬

을 도출하게 되는 것이다. Specifically, in the stiffness matrix derivation unit 30, for the mathematical function of the initial stiffness matrix designated by the administrator, the stiffness of the target structure

Value and spring constant of the target structure

The initial stiffness value of the target structure that satisfies Equation 7 by performing calculation while changing the value

And the initial spring constant value of the target structure

Is to find the initial stiffness value of the structure

And the initial spring constant value of the target structure

Initial stiffness matrix by

Is to derive.

은, 초기 상태의 대상 구조물과 동일한 구조적 거동 및 구조적 응답(대상 구조물의 응답특성)을 보일 수 있는 "구조해석모델"이 된다. Initial stiffness matrix derived by step S3 above

Is a "structural analysis model" that can show the same structural behavior and structural response (response characteristics of the target structure) as the target structure in the initial state.

로 표현되는 대상 구조물에 대한 "구조해석모델"이 구축되면, 대상 구조물에 실제 사용 하중이 작용할 때의 변형률을 계측하고, 이에 근거하여 대상 구조물의 구조적 특성변화 여부를 파악함으로써, 구조물의 상태를 모니터링하게 된다. Like this, the initial stiffness matrix

When a "structural analysis model" for the target structure represented by is built, the state of the structure is monitored by measuring the strain when the actual load is applied to the target structure, and determining whether the structural characteristics of the target structure change based on this. Is done.

에서 대상 구조물(200)에 기지(旣知)의 사용 하중

이 재하될 때의 변형률(사용상태 변형률)

를 대상 구조물에 설치된 변형률 계측 장치를 이용하여 계측한다(단계 S4). Specifically time

In the target structure 200, the use load of a known (旣知)

Strain at the time of loading (Strain in use state)

Is measured using a strain measurement device installed on the target structure (step S4).

는 연산장치(100)의 신호 수신부(10)로 전송되고, 연산장치(100)에 구비된 변형률-변형 변환 유닛(20)으로 전달되어, 변형률-변형 변환 유닛(20)에서의 연산을 통해서, 계측된 사용상태 변형률

를 변환하여 사용상태 변형

를 산출한다(단계 S5). 앞서 단계 S2-2 및 단계 S2-3을 통해서 대상 구조물의 변환행렬

을 도출해둔 상태이므로, 변형률-변형 변환 유닛(20)에서는, 계측된 사용상태 변형률

과, 이미 도출해둔 대상 구조물의 변환행렬

을 이용한 수학식 5의 연산을 통해서 대상 구조물의 변형

을 산출한다. 즉, 수학식 5는 결국 아래의 수학식 8로 표현되므로, 계측된 사용상태 변형률

과, 이미 도출해둔 대상 구조물의 변환행렬

을 이용하여 수학식 8의 연산에 의한 변환을 수행함으로써, 대상 구조물의 변형

을 산출하는 것이다. Measured operating state strain

Is transmitted to the signal receiving unit 10 of the computing device 100, transmitted to the strain-strain conversion unit 20 provided in the computing device 100, and through calculation in the strain-strain conversion unit 20, Measured operating state strain

To transform the usage state

Is calculated (step S5). Prior to step S2-2 and step S2-3, the transformation matrix of the target structure

Since is derived, in the strain-strain conversion unit 20, the measured strain in the used state

And, the transformation matrix of the target structure already derived

Deformation of the target structure through the operation of Equation 5 using

Yields That is, since Equation 5 is finally expressed as Equation 8 below, the measured strain in the state of use

And, the transformation matrix of the target structure already derived

By performing the transformation by the operation of Equation 8 using

Is to yield.

과, 그 때의 사용 하중

, 그리고 초기 강성행렬

의 형태로 도출해놓은 대상 구조물에 대한 "구조해석모델"을 이용하여 구조물의 손상 여부를 판단한다(단계 S6). In the structure damage determination unit 40 of the computing device 100, the calculated deformation of the target structure

And, the working load at that time

, And the initial stiffness matrix

It is determined whether the structure is damaged by using the "structure analysis model" for the target structure derived in the form of (step S6).

는 벡터로서, 재하된 사용 하중

과, 하중의 재하 위치로부터 공지의 기술을 통해 쉽게 구성할 수 있다. Working load

Is the vector, the loaded working load

And, it can be easily configured from the loading position of the load through a known technique.

과 그로 인하여 발생하는 대상 구조물의 변형

은 아래의 수학식 9의 관계를 가진다. According to Equation 6 described above, the working load

And the resulting deformation of the target structure

Has the relationship of Equation 9 below.

는, 사용 하중

이 작용하고 있는 시간

일 때의 대상 구조물에 대한 "사용상태 강성행렬"이다. In Equation 9 above

Is, the working load

This is working time

It is the "use state stiffness matrix" for the target structure when is.

이 작용하는 시간

의 시점에서, 대상 구조물에 균열 등의 손상이 발생하지 않았다면, 대상 구조물의 응답특성이 변화되지 않을 것이고, 결국 위 사용상태 강성행렬

은 초기 강성행렬

와 동일할 것이다. 반면에 사용 하중

이 작용하는 시간

의 시점에서 대상 구조물에 균열 등의 손상이 발생하였다면, 대상 구조물의 응답특성은 변화될 것이고, 위 사용상태 강성행렬

은 초기 강성행렬

와 다른 값을 가질 것이다. If the working load

Time to work

At the point of time, if damage such as a crack has not occurred in the target structure, the response characteristics of the target structure will not change, and eventually the above usage state stiffness matrix

Is the initial stiffness matrix

Will be the same as While working load

Time to work

If damage such as a crack occurs in the target structure at the point of time, the response characteristics of the target structure will change, and the above use state stiffness matrix

Is the initial stiffness matrix

Will have a different value than

을 산출한다(단계 S6-1). Based on this point, in the structure damage determination unit 40 to determine whether the structure is damaged, first, expressed by Equation 10 below.

Is calculated (step S6-1).

이 작용하는 시간

의 시점에서 대상 구조물에 균열 등의 손상이 발생하지 않았다면 대상 구조물의 구조적 거동 및 구조적 응답은 변화되지 않을 것이므로 사용상태 강성행렬

은 초기 강성행렬

와 동일하게 되며, 따라서 위 수학식 7에서 산출된

는 0의 값이 될 것이다. 반면에 사용 하중

이 작용하는 시간

의 시점에서 대상 구조물에 균열 등의 손상이 발생하였다면, 대상 구조물의 응답특성(구조적 거동 및 구조적 응답)은 변화되므로 사용상태 강성행렬

은 초기 강성행렬

와 다른 값을 가지게 되어 위 수학식 7에서 산출된

는 0이 아닌 값을 가질 것이다. Working load as previously described

Time to work

If no damage such as cracks has occurred in the target structure at the point of time, the structural behavior and structural response of the target structure will not change.

Is the initial stiffness matrix

Will be the same as, thus calculated in Equation 7 above

Will be a value of 0. While working load

Time to work

If damage such as a crack occurs in the target structure at the point of time, the response characteristics (structural behavior and structural response) of the target structure change, so the use state stiffness matrix

Is the initial stiffness matrix

Has a value different from that calculated in Equation 7 above

Will have a non-zero value.

을 기준으로 대상 구조물의 손상여부를 판단하여 그 판단결과를 관리자에게 전달하게 되는데, 산출된

의 값이 0(zero)일 경우에는 "구조물 손상 없음"으로 판단하고, 산출된

의 값이 0(zero)이 아닌 경우에는 "구조물 손상 발생"으로 판단하게 된다(단계 S6-2). 판단된 결과는 다양한 방식으로 관리자에게 통보된다. Therefore, the structure damage determination unit 40 calculated

It judges whether the target structure is damaged or not and transmits the judgment result to the manager.

If the value of is 0 (zero), it is judged as "no structure damage" and the calculated

If the value of is not 0 (zero), it is determined as &quot;structure damage has occurred" (step S6-2). The determined result is notified to the manager in various ways.

As described above, in the present invention, a structural analysis model is constructed based on strain, which is an important measure capable of detecting local damage and overall behavior change of the structure by reflecting the damage characteristics of the structure. In the present invention, the structure analysis model constructed as described above and the strain measurement values measured in real time at a plurality of measurement points of the target structure are used to determine whether the structure is damaged and to determine the location of the damage. Therefore, according to the present invention, it is possible to preemptively prepare and prepare an appropriate method to cope with the damage of the structure, and the effect of being able to maintain the structure more safely is exhibited.

10: signal receiver
20: strain-strain conversion unit
30: stiffness matrix derivation unit
40: structure damage judgment unit
100: computing device

Claims (4)

In the structure to be monitored for damage, a strain measurement device that can measure the strain at multiple measurement points is placed, and the initial load of the base on the target structure

Load and use the strain measurement device to determine the initial strain rate

Measuring the value;
The measured initial strain is transmitted to a computing device comprising a signal receiving unit, a strain-strain conversion unit, a stiffness matrix derivation unit, and a structure damage determination unit, and the initial strain through calculation in the strain-strain conversion unit of the computing device.

Initial transformation

Converting to and calculating;
Initial stiffness matrix representing the response characteristics of the target structure to the load through calculation in the stiffness matrix derivation unit equipped in the computing device

Deriving;
The working load of the base on the target structure at the time set by the manager

The strain in the state of use when it is loaded

Measuring using a strain measurement device installed on the target structure;
Measured operating state strain

Is transmitted to the computing device, and the strain-strain conversion unit of the computing device uses the measured strain rate through calculation.

Transform the state of use

To transform the state of use

Calculating; And
Initial stiffness matrix derived from the structural damage determination unit of the computing device as a structural analysis model for the used load, the calculated state of use, and the target structure

It includes; determining whether the target structure is damaged by using;
In the strain-strain conversion unit of the computing unit, the initial strain

Initial transformation

The step of converting to and calculating includes the process of dividing the target structure into a number of analysis elements determined by an administrator; For each divided analysis element, node deformation

And the strain at the strain measurement point existing within the analysis element

Transformation matrix representing the relationship between

A process of calculating and deriving; Transformation matrix for the entire target structure by integrating the transformation matrix of each derived analysis element

A process of calculating and deriving; And transformation matrix for the entire derived structure

And initial strain

Initial deformation of the target structure using

Includes the process of calculating;
Deformation of the use state in the strain-strain conversion unit of the computing device

The step of calculating is the measured strain in use state

And, the transformation matrix of the entire target structure already derived

Deformation of the target structure by the operation of Equation 8 using

Includes the process of calculating;
Initial stiffness matrix in stiffness matrix derivation unit

The step of deriving is, for the mathematical function of the initial stiffness matrix designated by the administrator, the stiffness of the target structure

Value and spring constant of the target structure

The initial stiffness value of the target structure that minimizes the difference between the initial stiffness matrix multiplied by the initial deformation of the target structure and the initial load applied to the target structure by performing calculation while changing the value

And the initial spring constant value of the target structure

The process of calculating; And the calculated initial stiffness value of the target structure

And the initial spring constant value of the target structure

As the initial stiffness matrix

Includes the process of deriving;
Initial stiffness matrix in the structural damage determination unit

The step of determining whether the target structure is damaged using Equation 10

The process of calculating; And calculated

If the value of is 0, it is judged as "no structure damage" and the calculated

If the value of is not 0, it is determined as "structural damage occurred" and has a configuration including a process of notifying the administrator of the determined result,
A method for monitoring whether a structure is damaged, characterized in that it monitors and determines whether structural damage has occurred in the target structure using strain measurement and a structural analysis model based on it.
(Equation 8)

(Equation 10)

(In Equation 5 and Equation 10

Is the measured strain in the state of use,

Is the transformation matrix of the entire target structure already derived,

Is the initial stiffness matrix,

Is the working load,

Is the working load

It is the deformation of the target structure caused by this.)
delete A strain measurement device that can measure strain at a plurality of measurement points and is disposed on a structure to be monitored for damage, and a computing device that receives signals from the strain measurement device and performs calculations for monitoring damage to the target structure. It consists of
The computing device includes a signal receiving unit, a strain-strain conversion unit, a stiffness matrix derivation unit, and a structure damage determination unit;
In the signal receiver, the initial load of the base on the target structure

The initial strain measured by the strain measuring device at the time of loading

Receive;
In the strain-strain conversion unit, the received initial strain

Initial transformation

Converted to and calculated;
In the stiffness matrix derivation unit, the initial stiffness matrix representing the response characteristics of the target structure to the load

Calculate and derive;
In the strain-strain conversion unit, the used load of the known structure is applied to the target structure at a time determined by the manager.

The strain in the state of use when it is loaded

When it is measured and transmitted by the strain measuring device installed in the target structure, the strain in the state of use measured through calculation

Transform the state of use

To transform the state of use

To yield;
In the structural damage determination unit, the used load, the calculated state of use deformation, and the initial stiffness matrix derived as a structural analysis model for the target structure

To determine whether the target structure is damaged or not;
Initial strain in strain-strain conversion unit

Initial transformation

When converting to and calculating, the process of dividing the target structure into the number of analysis elements determined by the manager; For each divided analysis element, node deformation

And the strain at the strain measurement point existing within the analysis element

Transformation matrix representing the relationship between

A process of calculating and deriving; Transformation matrix for the entire target structure by integrating the transformation matrix of each derived analysis element

A process of calculating and deriving; And transformation matrix for the entire derived structure

Initial strain on

The initial deformation of the target structure by multiplying by

To perform an operation including the process of calculating
Deformation of the use state in the strain-strain conversion unit of the computing device

When calculating, the measured strain in use

And, the transformation matrix of the entire target structure already derived

Deformation of the target structure by the operation of Equation 8 using

Yields;
Initial stiffness matrix in stiffness matrix derivation unit

When deriving, for the mathematical function of the initial stiffness matrix designated by the administrator, the stiffness of the target structure

Value and spring constant of the target structure

The initial stiffness value of the target structure that minimizes the difference between the initial stiffness matrix multiplied by the initial deformation of the target structure and the initial load applied to the target structure by performing calculation while changing the value

And the initial spring constant value of the target structure

The process of calculating; And the calculated initial stiffness value of the target structure

And the initial spring constant value of the target structure

As the initial stiffness matrix

An operation including the process of deriving is performed;
Initial stiffness matrix in the structural damage determination unit

When determining whether the target structure is damaged using

The process of calculating; And calculated

If the value of is 0, it is judged as "no structure damage" and the calculated

If the value of is not 0, it is determined as "structural damage occurred" and has a configuration including a process of notifying the administrator of the determined result,
A structural damage monitoring device, characterized in that it monitors and determines whether structural damage has occurred in a target structure using strain measurement and a structural analysis model based on the measurement.
(Equation 8)

(Equation 10)

(In Equation 8 and Equation 10

Is the measured strain in the state of use,

Is the transformation matrix of the entire target structure already derived,

Is the initial stiffness matrix,

Is the working load,

Is the working load

It is the deformation of the target structure caused by this.) delete

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