CN102297767A - Health monitoring method of rope system based on angle monitoring when support displaces angularly - Google Patents

Abstract

The health monitoring method of the cable system based on angle monitoring when the angular displacement of the support is based on angle monitoring. By monitoring the angular coordinates of the structural supports, it is determined whether the mechanical calculation benchmark model of the structure needs to be updated. It is only updated when the angular coordinates of the structural supports change. The mechanical calculation benchmark model of the structure, so as to obtain a new mechanical calculation benchmark model of the structure that takes into account the angular displacement of the structural support, and calculate the change matrix of the unit damage monitored quantity on the basis of this model. According to the approximate linear relationship between the current value vector of the monitored quantity and the initial vector of the monitored quantity, the change matrix of the monitored quantity per unit damage, the unit damage scalar and the current damage vector of the cable system to be obtained, a suitable multi-objective optimization algorithm can be used The algorithm quickly calculates the non-inferior solution of the current cable damage vector, based on which the position of the damaged cable and its damage degree can be determined more accurately when there is angular displacement of the support.

Description

Health monitoring method of cable system based on angle monitoring during bearing angular displacement

technical field

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. , cables, or rods that only bear tensile loads are supporting components, and this type of structure is expressed as a "cable structure" in the present invention for convenience. When there is an angular displacement of the support (for example, the rotation of the support around the coordinate axes X, Y, and Z is actually the angular displacement of the support around the coordinate axes X, Y, and Z), the present invention identifies the position of the cable structure based on angle monitoring. Supporting system (referring to all load-bearing cables and all supporting rods that only bear tensile loads. For convenience, this patent refers to all supporting components of this type of structure as "cable system", but in fact the cable system It not only refers to the supporting cables, but also includes the damaged cables in the rods that only bear the tensile load (for the truss structure, it refers to the damaged rods that only bear the tensile load), which belongs to the field of health monitoring of engineering structures.

Background technique

The cable system is usually a key component of the cable structure, and its failure often leads to the failure of the entire structure. Based on the structural health monitoring technology to identify the damaged cable in the cable system of the cable structure (as mentioned earlier, it also refers to the cable that only bears tension. loaded member) is a promising approach. Changes in the health status of the cable system will cause changes in the measurable parameters of the structure, such as changes in the angular coordinates of any imaginary straight line passing through each point of the cable structure (such as any one of the tangent planes at any point on the surface of the structure the change of the angular coordinate of the straight line passing through the point, or the change of the angular coordinate of the normal line at any point on the surface of the structure), in fact, the change of the structural angle contains the health status information of the cable system, that is to say, the structural angle data can be used to judge The health status of the structure can be based on angle monitoring (this invention refers to the monitored angle data as "monitored quantity", and the "monitored quantity" mentioned later refers to the monitored angle data) to identify damaged cables, and the monitored In addition to being affected by the health status of the cable system, the quantity is also affected by the angular displacement of the cable structure support (which often occurs). At present, there is no public and effective health monitoring system and method to solve this problem.

When there is angular displacement of the support, in order to have a reliable monitoring and judgment of the health status of the cable system of the cable structure, there must be a reasonable and effective establishment of the angle data change of the cable structure and the health status of all the cables in the cable system. The method of the relationship among them, the health monitoring system based on this method can give a more credible health assessment of the cable system.

Contents of the invention

Technical problem: The purpose of the present invention is to disclose a health monitoring method based on angle monitoring that can reasonably and effectively monitor the health of the cable system in the cable structure when the support of the cable structure has angular displacement. monitoring method.

Technical solution: the present invention consists of three parts. They are the knowledge base and parameter method required for establishing the cable system health monitoring system, the cable system health status evaluation method based on the knowledge base (including parameters) and the measured angle of the cable structure and the measured angular displacement of the cable structure support, and the health monitoring system. software and hardware parts.

The first part of the present invention: the method for establishing the knowledge base and parameters for cable system health monitoring, specifically as follows:

1. The method of establishing the initial mechanical calculation benchmark model A _o (such as the finite element benchmark model) and the current mechanical calculation benchmark model A ^t _o (such as the finite element benchmark model) of the cable structure. A _o is constant in the present invention. A ^t _o is constantly updated. The methods of establishing A _o , establishing and updating A ^t _o are as follows.

When establishing A _o , according to the actual measurement data of the cable structure when the cable structure is completed (including cable structure shape data, cable force data, tie rod tension data, cable structure support coordinate data, cable structure support angle coordinate data, cable structure model For cable-stayed bridges and suspension bridges, it is 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) and 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 should be carried out before the health monitoring system is established to obtain the actual measurement data of the cable structure (including Cable structure shape data, cable force data, pull rod tension data, cable structure support coordinate data, cable structure support angular coordinate data, cable structure modal data and other measured data are the bridge type of cable-stayed bridges and suspension bridges. Data, cable force data, bridge modal data, cable non-destructive testing 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) Build _Ao . 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 angular coordinate data of the cable structure support corresponding to A _o compose the initial cable structure support angular coordinate vector U _o .

During the service process of the cable structure, the current data of the support angle coordinates of the cable structure are continuously measured and obtained (all data form the current measured support angle coordinate vector U ^t of the cable structure, and the definition method of the vector U ^t is the same as that of the vector U ). For convenience, the current data of the angular coordinates of the cable structure support when the current mechanical calculation benchmark model was updated last time is recorded as the current angular coordinate vector U ^t _o of the cable structure support. The method of establishing and updating A ^t _o is: at the initial moment, A ^t _o is equal to A _o , and U ^t _o is equal to U _o ; during the service process of the cable structure, the angle coordinate data of the support angle of the cable structure is continuously measured to obtain the current cable structure. If U ^t is equal to U ^t _o , then A ^t _o does not need to be updated ^; if U ^t is not equal to U ^t _o , then A ^t _o needs to be updated. At this time, U ^t The difference with U _o is the support angular displacement of the cable structure support with respect to the initial position (corresponding to A _o ), the method to update A ^t _o is to impose displacement constraints on the cable structure support in A _o (the value is taken from the support seat angle displacement vector V ) to obtain the updated current mechanical calculation benchmark model A ^t _o , while updating A ^t _o , all element values of U ^t _o are also replaced by all element values of U ^t , that is, U ^t _o is updated, so that U ^t _o which correctly corresponds to A ^t _o is obtained.

"All monitored angle data of the structure" is described by K specified points on the structure, L specified straight lines passing through each specified point, and H angular coordinate components of each specified straight line. The change of the structure angle is all The change in all specified angular coordinate components of all specified lines for the specified point. Each time there are M (M=K×L×H) angle coordinate component measured or calculated values to represent the angle information of the structure. K and M shall not be less than the number N of supporting cables.

For the sake of convenience, the "monitored angle data of the structure" is simply referred to as "monitored quantity" in the present invention. When referring to "a certain matrix or a certain vector of the monitored quantity" later, it can also be read as "a certain matrix or a certain vector of the monitored angle".

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 (1)). 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.

(1)

In formula (1), 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 a specific j monitored quantities. 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 (2) for definition).

                  (2)

(2)

In formula (2), C _j ( j =1, 2, 3, …… ., M; M≥N ) is the current value of the jth monitored quantity in the cable structure, and this component C _j is related to C _oj according to the numbering rule Corresponding to the same "monitored quantity".

the

2. The method of establishing and updating the change matrix ΔC of the monitored damage of the cable structure unit .

The change matrix ΔC of the monitored damage of the cable structure unit is constantly updated, that is, the change matrix ΔC of the monitored damage of the cable structure unit is updated while updating the current mechanical calculation benchmark model A ^t _o . The specific method is as follows:

Several calculations are performed on the basis of the current mechanical calculation benchmark model A ^to _of the cable structure, and the number of calculations is numerically equal to the number of all supporting cables. Each calculation assumes that only one supporting cable in the cable system has unit damage D _u (for example, 5%, 10%, 20% or 30% damage is taken as the unit damage), and the damaged cable in each calculation is different from other times. For cables that are damaged during calculation, each calculation uses mechanical methods (such as finite element method) to calculate the current calculated values of all monitored quantities of the cable structure, and the current calculated values of all monitored quantities obtained by each calculation form a monitored Calculate the current vector of the monitored quantity (when it is assumed that the i-th cable has unit damage, the formula (3) can be used to express the current vector of the monitored quantity calculated C _t ⁱ ); each time the calculated current vector of the monitored quantity is calculated minus the initial vector of the monitored quantity , the obtained vector is the monitored variable change vector under this condition (marked by the position or number of the supporting cable with unit damage) (when the i-th cable has unit damage, use δC _i to represent the monitored variable change vector, See formula (4) for the definition, formula (4) is obtained by subtracting formula (1) from formula (3), and each element of the monitored quantity change vector represents the unit damage of the cable assumed to have unit damage during calculation. The amount of change of the monitored quantity corresponding to the element is caused; there are N roots of cables, and there are N monitored quantity change vectors. Since there are M monitored quantities, each monitored quantity change vector has M elements. These N monitored variable change vectors form a unit damage monitored variable change matrix ΔC with M×N elements in turn. The definition of ΔC is shown in formula (5).

            (3)

(3)

The element C _tj ⁱ ( i =1, 2, 3, ...., N; j =1, 2, 3, ...., M; M≥N ) in formula (3) means that since the i -th cable has a unit When damaged, the current calculated amount of the jth monitored amount corresponding to the numbering rule.

                                        (4)

(4)

             (5)

(5)

In formula (5), ΔC _j,i ( i =1, 2, 3, ...., N; j =1, 2, 3, ...., M; M≥N ) means that only because the i -th cable has The change (algebraic value) of the calculated current value of the jth monitored quantity corresponding to the numbering rule caused by unit damage. The monitored variable change vector δC _i is actually a column in the matrix ΔC , that is to say, formula (5) can also be written as formula (6).

        (6)

(6)

3. The approximate linear relationship between the current value vector C of the monitored quantity (calculated or measured) and the initial vector C _o of the monitored quantity, the change matrix of the monitored quantity for unit damage ΔC , the unit damage scalar D _u and the current damage vector d , as shown in the formula (7) or formula (8). For the definition of the current damage vector d of the cable system, refer to formula (9).

                                    (7)

(7)

                                    (8)

(8)

                 (9)

(9)

In formula (9), d _i ( i =1, 2, 3, …., N ) is the current damage of the i -th cable (or tie rod) in the cable system; when d _i is 0, it means no damage, which is 100% When the value is between 0 and 100%, it means that the cable has completely lost its bearing capacity, and when it is between 0 and 100%, it means that the corresponding proportion of the bearing capacity is lost.

If the cable damage is set to 100%, it means that the cable completely loses its bearing capacity, then when the actual damage is not too large (for example, the damage is not greater than 30%), since the cable structure material is still in the linear elastic stage, the deformation of the cable structure is also small , the error between such a linear relationship represented by formula (7) or formula (8) and the actual situation is small. Use the linear relationship error vector e defined by formula (10) to express the error of the linear relationship shown in formula (7) or formula (8).

                              (10)

(10)

In the formula (10), abs() is an absolute value function, and the absolute value is taken for each element of the vector obtained in the brackets.

the

The second part of the present invention: a method for evaluating the health status of the cable system based on the knowledge base (including parameters) and measured monitored quantities.

Since there is a certain error in the linear relationship represented by formula (7) or formula (8), the current damage vector d cannot be directly obtained by simply solving formula (7) or formula (8) and the current value vector C of the measured monitored quantity. If this is done, the elements in the obtained current damage vector d may even have relatively large negative values, that is, negative damage, which is obviously unreasonable. Therefore, it is a reasonable solution to obtain an acceptable solution of the current damage vector d (that is, with a reasonable error, but the location of the damaged cable and its damage degree can be determined more accurately from the cable system), and the formula (11) can be used to express this method.

                              (11)

(11)

In Equation (11), abs() is an absolute value function, and the vector g describes the reasonable deviation from the ideal linear relationship (Equation (7) or Equation (8)), which is defined by Equation (12).

(12)

g _j ( j =1, 2, 3, …., M ) in formula (12) describes the maximum allowable deviation from the ideal linear relationship shown in formula (7) or formula (8). The vector g can be selected according to the error vector e defined by formula (10).

When the initial vector C _o of the monitored quantity, the change matrix ΔC of the monitored quantity with unit damage, the current value vector C of the measured monitored quantity and the unit damage D _u (set before calculating ΔC , which is a scalar quantity) are known, an appropriate algorithm can be used (For example, multi-objective optimization algorithm) Solve formula (11) to obtain an acceptable solution of the current damage vector d , so as to determine the position and damage degree of the damaged cable.

the

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

The hardware part includes the monitoring system (including the monitored quantity monitoring system, the cable structure support angular coordinate monitoring system), signal collector and computer, etc. Real-time or quasi-real-time monitoring of each monitored quantity is required, and real-time or quasi-real-time monitoring of the angular coordinates of each cable structure support is required.

The software should have the following functions: the software part first analyzes the real-time or quasi-real-time data from the monitoring system to obtain the actual measured support angle coordinate vector U ^t of the current cable structure and the current value vector C of the monitored quantity, and then reads the pre-stored index The mechanical calculation benchmark model A _o of the structure, the initial cable structure support angular coordinate vector U _o , the current mechanical calculation benchmark model A ^t _o , the current cable structure support angular coordinate vector U ^t _o , and the cable system unit damage monitored quantity change matrix ΔC , the initial vector C _o of the monitored quantity and the unit damage value D _u , compare the measured support angle coordinate vector U ^t of the current cable structure with the current cable structure support angle coordinate vector U ^t _o , when U ^t and U ^t _o are the same , according to the appropriate algorithm (such as multi-objective optimization algorithm) to solve the formula (11), the non-inferior solution of the current damage vector d of the cable system is obtained, that is, with reasonable error, but the damage can be determined more accurately from the cable system The position of the cable and the solution of its damage degree; when U ^t and U ^t _o are different, the current mechanical calculation benchmark model A ^t _o and the current cable structure support angle coordinate vector U ^t _o are updated first, and then in the new A On the basis of ^t _o , update ΔC according to the above-mentioned "method of establishing and updating the change matrix ΔC of the monitored quantity of cable structure unit damage", and also solve the formula (11) according to the appropriate algorithm (such as multi-objective optimization algorithm) to obtain the current value of the cable system The non-inferior solution of the damage vector d , that is, the solution with a reasonable error, but can accurately determine the position of the damaged cable and its damage degree from the cable system.

the

The inventive method specifically comprises:

a. Assuming that there are N cables in total, first determine the numbering rules of the cables, and number all the cables in the cable structure according to this rule, and the numbers will be used to generate vectors and matrices in subsequent steps;

b. Determine the specified measured point, and number all the specified points; determine the measured straight line of each measured point, and number all the specified measured straight lines; determine the measured angular coordinate component of each measured straight line, and give All measured angle coordinate components are numbered; the above-mentioned numbers will be used to generate vectors and matrices in subsequent steps; "all monitored angle data of the structure" is composed of all above-mentioned measured angle coordinate components; for convenience, in the present invention The "monitored angle data of the structure" is referred to as "monitored quantity"; the number of measuring points shall not be less than the number of cables; the sum of the number of all measured angle coordinate components shall not be less than the number of cables;

c. Directly measure and calculate the initial values of all the monitored quantities of the cable structure to form the initial vector C _o of the monitored quantity; at the same time as the initial vector C _o of the monitored quantity is obtained by actual measurement, the initial cable force of all the cables of the cable structure is obtained by actual measurement Data, the initial geometry data of the structure, the initial cable structure support coordinate data and the initial cable structure support angular coordinate data, the initial cable structure support angular coordinate data form the initial cable structure support angular coordinate vector U _o ;

d. Establish the initial mechanical calculation benchmark model A _o of the cable structure based on the cable structure design drawing, as-built drawing, measured data of the cable structure, non-destructive testing data of the cable, and the initial cable structure support angular coordinate vector U _o and establish it for the first time The current mechanical calculation benchmark model A ^t _o of the cable structure, the measured data of the cable structure at least include the initial cable force data of all cables of the cable structure, the initial cable structure support coordinate data, the initial cable structure support angular coordinate data and the cable structure Initial geometric data; when the current mechanical calculation benchmark model A ^t _o of the cable structure is established for the first time, the current mechanical calculation benchmark model A ^t _o of the cable structure is equal to the initial mechanical calculation benchmark model A _o of the cable structure; corresponding to the cable structure The cable structure support angular coordinate data of the current mechanical calculation benchmark model A ^t _o constitutes the current cable structure support angular coordinate vector U ^t _o , when the current mechanical calculation benchmark model A ^t _o of the cable structure is established for the first time, U ^t _o is is equal to U _o ;

e. From here, enter the cycle from step e to step k; during the service process of the structure, the current data of the angular coordinates of the cable structure supports are continuously measured, and all the current data of the angular coordinates of the cable structure supports form the current measured support of the cable structure Angular coordinate vector U ^t ;

f. According to the measured support angle coordinate vector U ^t of the current cable structure, update the current mechanical calculation benchmark model A ^t _o and the current cable structure support angle coordinate vector U ^t _o when necessary;

g. Carry out several mechanical calculations on the basis of the current mechanical calculation benchmark model A ^t _o , and obtain the change matrix ΔC of the monitored quantity of cable structure unit damage and the unit damage scalar D _u through calculation;

h. Obtain the current measured values of all specified monitored quantities of the cable structure through actual measurement, and form the current numerical value vector C of the monitored quantities;

i. Define the current damage vector d of the cable system. The number of elements of the current damage vector d of the cable system is equal to the number of cables. There is a one-to-one correspondence between the elements of the current damage vector d of the cable system and the cables. The current damage vector d of the cable system The element value represents the damage degree or health status of the corresponding cable;

j. Based on the approximation between the current value vector C of the monitored quantity and the initial vector C _o of the monitored quantity, the change matrix of the monitored quantity ΔC per unit damage of the cable structure, the unit damage scalar D _u and the current damage vector d of the cable system to be obtained The approximate linear relationship can be expressed as formula 1. In formula 1, other quantities except d are known, and the current damage vector d of the cable system can be calculated by solving formula 1; since the element value of the current damage vector d represents the corresponding Therefore, according to the current damage vector to determine which cables are damaged and their damage degree, the health monitoring of the cable system in the cable structure is realized; if the value of an element of the current cable damage vector is 0, it means that the element The corresponding cable is intact and undamaged; if its value is 100%, it means that the cable corresponding to the element has completely lost its bearing capacity; if its value is between 0 and 100%, it means that the cable is lost The carrying capacity of the corresponding proportion;

                                 式1

Formula 1

k. Go back to step e and start the next cycle from step e to step k.

the

In step f, according to the measured support angle coordinate vector U ^t of the current cable structure, the specific method for updating the current mechanical calculation benchmark model A ^t _o and the current cable structure support angle coordinate vector U ^t _o when necessary is as follows:

f1. After obtaining the actual measured support angle coordinate vector U ^t of the current cable structure in step e, compare U ^t with U ^t _o , if U ^t is equal to U ^t _o , then A ^t _o and U ^t _o remain unchanged;

f2. After obtaining the measured support angle coordinate vector U ^t of the current cable structure in step e, compare U ^t and U ^t _o , if U ^t is not equal to U ^t _o , then update A ^t _o and U ^t _o , the update method is: first calculate the difference between U ^t and U _o , the difference between U ^t and U _o is the current support angular displacement of the cable structure support with respect to the initial position, and use the support angular displacement vector V to represent the support angular displacement, There is a one-to-one correspondence between the elements in the support angular displacement vector V and the support angular displacement components, and the value of an element in the support angular displacement vector V corresponds to the angular displacement of a specified support around a specified direction; update The method of A ^t _o is to impose the current support angular displacement constraint on the cable structure support in A _o , the value of the current support angular displacement constraint is taken from the value of the corresponding element in the support angular displacement vector V , for A _o The updated current mechanical calculation benchmark model A ^t _o is obtained after the support angular displacement constraint is applied to the cable structure support. When A ^t _o is updated, the values of all elements of U ^t _o are also replaced by the corresponding values of all elements of U ^t in step e , that is, U ^t _o is updated, so that U ^t _o corresponding to A ^t _o is obtained correctly.

the

In step g, on the basis of the current mechanical calculation benchmark model A ^t _o , the specific method to obtain the change matrix ΔC of the unit damage monitored quantity of the cable structure and the unit damage scalar D _u through several mechanical calculations is as follows:

g1. The cable structure unit damage monitored variable matrix ΔC is constantly updated, that is, while updating the current mechanical calculation benchmark model A ^t _o and the current cable structure support angular coordinate vector U ^t _o , the cable structure unit damage must be updated at the same time The monitored quantity change matrix ΔC and the unit damage scalar D _u ;

g2. Carry out several mechanical calculations on the basis of the current mechanical calculation benchmark model A ^t _o of the cable structure. The number of calculations is numerically equal to the number of all cables. There are N calculations with N cables. Each calculation assumes that the cable system is Only one cable has a unit damage scalar D _u , and the damaged cable in each calculation is different from the damaged cable in other calculations. Each calculation obtains the current calculation values of all monitored quantities in the cable structure, and each calculation obtains The current calculation values of all the monitored quantities form a current vector for the calculation of the monitored quantities;

g3. Calculate the current vector of the monitored quantity obtained by each calculation minus the initial vector of the monitored quantity to obtain a monitored quantity change vector; if there are N cables, there will be N monitored quantity change vectors;

g4. A cable structure unit damage monitored quantity change matrix ΔC with N columns is formed in turn by these N monitored quantity change vectors; each column of the cable structure unit damage monitored quantity change matrix ΔC corresponds to a monitored quantity change vector.

Beneficial effects: the method disclosed in the present invention can very accurately monitor and evaluate the health status of the cable system (including the position and damage of all damaged cables) degree), the system and method disclosed in the present invention are very beneficial for the effective health monitoring of the cable system in the presence of bearing angular displacement.

Detailed ways

Aiming at the health monitoring of the cable system of the cable structure when there is angular displacement of the support, the invention discloses a system and method capable of reasonably and effectively monitoring the health status of each cable in the cable system of the cable structure. 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.

The present invention employs an algorithm for monitoring the health of a cable system in a cable structure. During specific implementation, the following steps are one of various steps that may be taken.

Step 1: Assuming that there are N cables in total, first determine the numbering rule of the cables, and number all the cables in the cable structure according to this rule, and the numbers will be used to generate vectors and matrices in subsequent steps. Determine the designated measured points (that is, all designated points representing the angular displacement of the structure, with K designated points), and number all designated points; determine the measured straight line of each measured point (set each measured point with L specified straight line), number all specified measured straight lines; determine the measured angular coordinate components of each measured straight line (assuming that each measured straight line has H angular coordinate components), and number all measured angular coordinate components . The above numbers will also be used to generate vectors and matrices in subsequent steps. The "all monitored angle data of the structure" is described by the K specified points on the structure determined above, the L specified straight lines passing through each specified point, and the H angular coordinate components of each specified straight line. The change is the change of all specified angle coordinate components of all specified points and all specified lines. Each time there are M (M=K×L×H) angle coordinate component measured or calculated values to represent the angle information of the structure. K and M shall not be less than the number N of supporting cables. For convenience, the "monitored angle data of the structure" is referred to as "monitored quantity" in the present invention. 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 of the specified point relative to the direction of gravitational acceleration is measured, which is actually an inclination measurement here.

Step 2: Get the initial values of all the monitored quantities of the cable structure by direct measurement _and calculation, and form the initial vector C o _of the monitored quantity; The cable force data, the initial geometric data of the structure (for cable-stayed bridges, the initial bridge type data), the initial cable structure support coordinate data and the initial cable structure support angular coordinate data, the initial cable structure support angular coordinate data constitute the initial cable structure. Structural support angular coordinate vector U _o .

Step 3: According to the cable structure design drawing, as-built drawing and the measured data of the cable structure (including the initial geometry data of the structure, strain data, initial cable force of all cables, structural modal data, etc.), the cable-stayed bridge and suspension bridge In terms of bridge type data, strain data, cable force data, bridge modal data), cable non-destructive testing data, initial cable structure support coordinate data and initial cable structure support angular coordinate vector U _o to establish the cable structure The initial mechanical calculation benchmark model A _o of the cable structure and the first establishment of the current mechanical calculation benchmark model A ^t _o of the cable structure; when the current mechanical calculation benchmark model A ^t _o of the cable structure is established for the first time, the current mechanical calculation benchmark model A ^t _o is the same as the initial mechanical calculation benchmark model A _o of the cable structure; the cable structure support angular coordinate data corresponding to the current mechanical calculation benchmark model A ^t _o of the cable structure forms the current cable structure support angular coordinate vector U ^t _o ; When the current mechanical calculation benchmark model A ^t _o of the cable structure is established for the first time, U ^t _o is equal to U _o ; the calculation data of the structure calculated based on the initial mechanical calculation benchmark model A _o must be very close to the measured data, and the error is generally not greater than 5%.

The fourth step: during the service process of the structure, the current data of the support angle coordinates of the cable structure are continuously measured, and all the data form the current measured support angle coordinate vector U ^t of the cable structure;

Step 5: According to the measured support angular coordinate vector U ^t of the current cable structure, update the current mechanical calculation benchmark model A ^t _o and the current cable structure support angular coordinate vector U ^t _o when necessary. After the actual measured support angle coordinate vector U ^t of the current cable structure obtained in the fourth step, compare U ^t and U ^t _o , if U ^t is equal to U ^t _o , then A ^t _o and U ^t _o remain unchanged; if U If ^t is not equal to U ^t _o , then A ^t _o and U ^t _o need to be updated. The updating method is: first calculate the difference between U ^t and U t _o , and the difference between U ^t and U t _o is the initial position of the cable structure support. The current angular displacement of the support, the angular displacement of the support is represented by the angular displacement vector V of the support. There is a one-to-one correspondence between the elements in the angular displacement vector V of the support and the components of the angular displacement of the support. The value of the element corresponds to the angular displacement of a specified support around a specified direction; the method of updating A ^t _o is to impose the current support angular displacement constraint on the cable structure support in A _o , and the value of the current support angular displacement constraint Take the value of the corresponding element in the support angular displacement vector V , and apply the support angular displacement constraint to the cable structure support in A _o to obtain the updated current mechanical calculation benchmark model A ^t _o , while updating A ^t _o , The values of all elements of U ^t _o are also replaced by the corresponding values of all elements of U ^t in the fourth step, that is, U ^t _o is updated, so that U ^t _o correctly corresponding to A ^t _o is obtained.

Step 6: Carry out several mechanical calculations on the basis of the current mechanical calculation benchmark model A ^t _o , and obtain the change matrix ΔC of the monitored quantity of cable structure unit damage and the unit damage scalar D _u through calculation . The specific method is as follows: the change matrix ΔC of the monitored unit damage of the cable structure is constantly updated, that is, while updating the current mechanical calculation benchmark model A ^t _o and the current cable structure support angular coordinate vector U ^t _o , the cable structure must be updated at the same time Unit damage monitored variable change matrix ΔC and unit damage scalar D _u ; several mechanical calculations are performed on the basis of the current mechanical calculation benchmark model A ^t _o of the cable structure, and the number of calculations is numerically equal to the number of all cables. There are N cables There are N times of calculations, and each calculation assumes that only one cable in the cable system has unit damage D _u (for example, 5%, 10%, 20% or 30% damage is taken as unit damage), and the occurrence of damage in each calculation The cable is different from the damaged cable in other calculations. Each calculation obtains the current calculated values of all monitored quantities in the cable structure, and the current calculated values of all monitored quantities obtained by each calculation form a monitored quantity calculation current vector C ; Calculate the current vector of the monitored quantity and subtract the initial vector of the monitored quantity from each calculation to obtain a monitored quantity change vector; if there are N cables, there will be N monitored quantity change vectors; from these N monitored quantity change vectors in turn A unit damage monitored quantity change matrix ΔC having N columns is formed; each column of the unit damage monitored quantity change matrix corresponds to a monitored quantity change vector.

Step 7: Establish linear relationship error vector e and vector g . Using the previous data (monitored quantity initial vector C _o , unit damage monitored quantity change matrix ΔC ), while performing each calculation in the sixth step, that is, each calculation assumes that only one cable has unit damage in the cable system D _u , the damaged cable in each calculation is different from the damaged cable in other calculations, each calculation uses mechanical methods (such as finite element method) to calculate the current values of all specified monitored quantities in the cable system in the cable structure Value, each calculation forms a monitored quantity and calculates the current vector C. At the same time, each calculation forms a damage vector d . Among all the elements of the damage vector d , the value of only one element is D _u , and the value of other elements is 0. The element whose value is D _u in the damage vector d corresponds to the unit damage degree D _u of the only damaged cable in this calculation; put C, C _o , ΔC , D _u , d into formula (10), and a linear relationship is obtained Error vector e , a linear relationship error vector e is obtained for each calculation; there are N calculations with N cables, and there are N linear relationship error vectors e , and these N linear relationship error vectors e are added to obtain a vector , the new vector obtained after 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 .

Step 8: Install the hardware part of the cable structure health monitoring system. The hardware part includes at least: monitored quantity monitoring system (including angle measurement sensor, signal conditioner, etc.), cable structure support angular coordinate monitoring system (including angle measurement sensor, signal conditioner, etc.), signal (data) collector, computer and communication alarm equipment. Each monitored quantity and the support angle coordinates of each cable structure must be monitored by the monitoring system. The monitoring system transmits the monitored signal to the signal (data) collector; the signal is transmitted to the computer through the signal collector; The health monitoring software of the cable system responsible for running the cable structure includes recording the signal transmitted by the signal collector; when the cable is detected to be damaged, the computer controls the communication alarm device to alarm the monitoring personnel, the owner and (or) the designated personnel.

Step 9: Save the parameters of the initial vector C _o of the monitored quantity, the change matrix of the monitored quantity of unit damage ΔC , and the scalar quantity D _u of the unit damage in the form of data files on the hard disk of the computer running the health monitoring system software.

Step 10: compile and install the health monitoring system software of the cable system based on angle monitoring when running the angular displacement of the support on the computer, this software will complete the "health monitoring of the cable system based on angle monitoring during the angular displacement of the support" of the present invention The monitoring, recording, control, storage, calculation, notification, alarm and other functions required by the task (that is, all the work that can be done by computer in this specific implementation method)

The eleventh step: Obtain the current measured values of all specified monitored quantities of the cable structure through actual measurement, and form "the current numerical value vector C of the monitored quantities";

Step 12: According to the current value vector C of the monitored quantity, the initial vector C _o of the monitored quantity, the change matrix of the monitored quantity of unit damage ΔC , the unit damage scalar D _u and the current damage vector d of the cable system (by the current damage vector d of all cables The approximate linear relationship (Equation (7)) exists among the cable system’s current damage vector d according to the multi-objective optimization algorithm, that is, there is a reasonable error, but it can be determined more accurately The location of the damaged cable and the solution of its damage degree.

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

According to the objective programming method, Equation (7) can be transformed into the multi-objective optimization problem shown in Equation (13) and Equation (14). In Equation (13), γ is a real number, R is a real number field, and the space region Ω limits the vector The value range of each element of d (this embodiment requires that each element of vector d is not less than 0 and not greater than 1). Equation (13) means to find a minimum real number γ so that Equation (14) is satisfied. G(d) in formula (14) is defined by formula (15), the product of weighted vector W and γ in formula (14) represents the allowable deviation between G(d) and vector g in formula (14), the definition of g See formula (12), its value has been calculated in the seventh 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. The current damage vector d of the cable system can be obtained by using the goal programming method.

(13)

                                        (14)

(14)

                            (15)

(15)

The number of elements of the current damage vector d of the cable system is equal to the number of cables. There is a one-to-one correspondence between the elements of the current damage vector d of the cable system and the cables. The value of the elements of the current damage vector d of the cable system represents the damage degree or health of the corresponding cable. state. If the value of an element of the current damage vector d of the solved cable system is 0, it means that the cable corresponding to this element is intact and has no damage; if its value is 100%, it means that the cable corresponding to this element has been damaged. Complete loss of bearing capacity; if its value is between 0 and 100%, it means that the cable has lost a corresponding proportion of its bearing capacity.

Step 13: 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 14: Under the specified conditions, the computer in the health monitoring system automatically operates the communication alarm equipment to alarm the monitoring personnel, the owner and (or) the designated personnel.

Step 15: Go back to step 4 and start the cycle from step 4 to step 15. the

Claims (3)

1. A method based on the bearing angle of the angular displacement of the cable monitoring system health monitor, characterized in that said method comprises:

   a. provided there are N roots Faso, first determine the number of cable rules, this rule will search all of the cable structure number, which will be used in subsequent steps to generate vectors and matrices;

   b. Determines if the specified point being measured, to all designated point number; identified through each measuring point is measured straight to all the specified line number is measured; determined for each line to be measured by measuring the angle coordinate component, to All angles are measured coordinate component number; the number will be used in subsequent steps to generate vectors and matrices; "structure of the full angle data to be monitored" by the angle coordinate component of all components to be measured; for convenience, in the present invention, the "structural angle data to be monitored," referred to as "the amount to be monitored"; number of measurement points not less than the number of cable; measured angular coordinates of all the number of components and shall not be less than the number of cable;

   c. direct measurement of all the cable structure calculated the amount of the initial value to be monitored, the amount of the initial vector components to be monitoredC _o ; The actual amount to be monitored to get the initial vectorC _o At the same time, all of the measured cable cable structures obtained initial cable force data, the initial geometric data structures, the initial coordinate data cable structures bearing support structure and the initial angular coordinates data cable, cable structures bearing the initial composition of the initial angular coordinate data cable structure bearing angular coordinate vectorU _o；

   d. According cable structure design drawings, as-built drawings and cable structures measured data cable for non-destructive testing and initial data cable structures bearing angular coordinate vectorU _oEstablishing the initial mechanical cable structures calculated on the basis of model A_oCable structures established for the first time calculated on the basis of current mechanical Model A^t _o, Cable structures measured data structure including at least all the cable cable cable force the initial data, the initial coordinate data cable structures bearing, bearing the initial angular coordinate data cable structure and the structure of the initial geometry data cable; cable structure is first created A mechanical model of the current basis of calculation^t _oWhen the current mechanical cable structures calculated on the basis of model A^t _oCable structure is equal to the initial baseline model A mechanical calculations_o; Cable structure corresponds to the current benchmark model A mechanical calculations^t _oBearing angle of the cable structure composed of the current coordinate data cable structures bearing angular coordinate vectorU ^t _o, The first to establish the current mechanical cable structures calculated on the basis of model A^t _oWhenU ^t _oIs equal toU _o；

   e. from here from the first step to step k e cycle; during service in the structure, and continuously measured angular coordinates to get cable structures bearing current data cable structures bearing angular coordinates of all current data structure composed of current index measured bearing angular coordinate vectorU ^t ；

   f. measured according to the current cable structure bearing angular coordinates vectorU ^t When necessary to update the current benchmark model A mechanics calculations^t _oAnd the current cable structure bearing angular coordinate vectorU ^t _o；

   g. calculated on the basis of the current mechanics Model A^t _oOn the basis of several mechanical calculations, cable structures obtained by calculating the amount of change in the monitored unit matrix damageΔCAnd unit damage scalarD _u ；

   h. measured cable structures obtained by monitoring the amount of all specified current measured value, the composition of the current value of the monitored quantity vectorC；

   i. define the cable system's current injury vectord, The cable system is currently injury vectordNumber of elements equal to the number of cable, cable system is currently injury vectordElements and one to one relationship between cable, cable system is currently injury vectordValues ​​represent the elements of the corresponding degree of injury or health claim status;

   j. based on the current value of the monitored quantity vectorCThe same amount of the initial vector to be monitoredC _o , Cable structure unit amount of damage was monitored change matrixΔC, Unit damage scalarD _u And the unknown vector of the cable system's current injurydApproximately linear relationship exists between the approximate linear relationship can be expressed by formula 1, formula 1, in addition todOutside the other quantities are known, one can calculate the formula for solving the current system damage vectors cabled; Because of the current injury vectordValues ​​represent the corresponding elements of the damage claim, so according to the current injury vectors determine what cable damage and injury, namely, the achievement of the cable structure retrieval system health monitoring; cord injury if the current value of the vector is an element 0, which means that the element corresponding to the cable is intact, no damage; if its value is 100%, it means that the element corresponding to the load capacity index has completely lost; if its value is between 0 and 100%, indicates that the corresponding proportion of the loss of cable carrying capacity;

   

   Formula 1

   k. return to step e, e began the first step to the next iteration step k​​.
2. (2) as claimed in claim 1, wherein the angular displacement of the seat of the cable angle-based monitoring system health monitoring, characterized in that in step f, the current measured bearing angle cable structure coordinate vectorU ^t When necessary to update the current benchmark model A mechanics calculations^t _oAnd the current cable structure bearing angular coordinate vectorU ^t _oThe specific method is:

   f1. measured in step e to get the current cable structure measured bearing angle coordinate vectorU ^t After comparisonU ^t And atU ^t _o, IfU ^t EqualU ^t _o, Then A^t _oAndU ^t _oRemain unchanged;

   f2. measured in step e to get the current cable structure measured bearing angle coordinate vectorU ^t After comparisonU ^t AndU ^t _o, IfU ^t Is not equal toU ^t _o, You need the A^t _oAndU ^t _oUpdate, the method is: first calculateU ^t AndU _oThe difference,U ^t AndU _oThe difference is the initial position of cable structures bearing on the current bearing angular displacement, angular displacement vector with supportVIndicates bearing angular displacement, bearing angular displacement vectorVThe angular displacement component elements and bearing one relationship between, bearing angular displacement vectorVValue of an element in the bearing corresponds to a specified direction around a specified angular displacement; profile A^t _oA method is_oThe cable structure bearing bearing angular displacement constraints applied current, the current bearing angular displacement constraints on the values ​​taken from the bearing angular displacement vectorVThe value in the corresponding element of the A_oThe cable structure bearing bearing angular displacement constraints applied to be updated after the current benchmark model A mechanical calculations^t _oUpdate A^t _oAt the same time,U ^t _oAll values ​​are also elements of step with the first eU ^t All elements of the value corresponds to the place, that is updatedU ^t _o, Thus obtaining the right corresponds to the A^t _oOfU ^t _o。
3. 3 according to claim 1, wherein the angular displacement of the seat of the cable angle-based monitoring system health monitoring, characterized in that in step g, calculated on the basis of the current model of the mechanical A^t _oBased on mechanical calculations obtained through several units of cable structures to monitor the amount of damage was change matrixΔCAnd unit damage scalarD _u The specific method is:

   g1. cord injury unit structure being monitored changes in the amount of matrixΔCIs constantly updated, which updates the current mechanical calculations in the baseline model A^t _oAnd the current cable structure bearing angular coordinate vectorU ^t _oAt the same time, you must also update the cable structure unit amount of damage was monitored change matrixΔCAnd unit damage scalarD _u ；

   g2. mechanics in cable structures calculated on the basis of the current Model A^t _oOn the basis of several mechanical, calculated numerically equal to the number of the number of all indexes haveNRoot cable thereNOf calculations, every calculation assumes that only one cable system damage scalar units SuoD _u , Damage occurs every time the calculation of the cable is different from other sub-calculations to injury of the cable, each cable structure in the calculated amount of current to be monitored all the calculated values​​, calculated each time the amount of all the monitored value of the current component calculation an amount calculated by monitoring the current vector;

   g3. every time calculated by monitoring the amount calculated by subtracting the current vector obtained by monitoring the amount of the initial vector vector of a monitored volume changes; thereNRoot cable thereNA change in the monitored quantity vectors;

   g4. by theseNA change in the amount to be monitored in turn composed of a vectorNColumns cable structure unit volume change matrix damage was monitoredΔC; Cable structure units to monitor the amount of damage was change matrixΔCEach column corresponds to an amount of change vectors to be monitored.