Structural damage determination method, processor and computer program product

Abstract

The invention discloses a structural damage determination method, a processor and a computer program product, and belongs to the technical field of structural health monitoring and nondestructive detection.The structural damage determination method comprises the steps that a nondestructive reference vibration mode of a target structure at a first set of preset measuring points is obtained; when the state of the target structure is unknown, a first measurement vibration mode is obtained on the first set of preset measurement points, and the first vibration mode curvature of the first measurement vibration mode and the lossless reference vibration mode at the first set of preset measurement points is calculated; determining an initial damage interval from the first group of preset measuring points based on the first vibration mode curvature; acquiring a second measurement vibration mode on a second group of preset measurement points in the initial damage interval, and calculating a second vibration mode curvature of the second measurement vibration mode and the lossless reference vibration mode at corresponding positions; and determining a target damage position from the initial damage interval based on the second vibration mode curvature.

Description

Technical Field

[0001] This invention relates to the field of structural health monitoring and non-destructive testing technology, and in particular to a method for determining structural damage, a processor, and a computer program product. Background Technology

[0002] Supertall buildings have lifespans of several decades. However, during their service life, they are inevitably subjected to varying degrees of damage due to their own loads, natural disasters such as earthquakes and typhoons, harsh environments, and other human factors. The continuous accumulation of damage gradually degrades the building's performance, affecting human activities within it, and in severe cases, jeopardizing structural safety and causing incalculable loss of life and property. Damage identification for supertall buildings is a crucial measure to prevent serious accidents and ensure the maintainability and safety of supertall structures. Vibration signal-based damage identification can perform global damage identification of the structure without damaging the structure itself, and is currently the primary method for building structural damage identification.

[0003] Methods for identifying damage to building structures are generally limited by the scale of sensor network deployment. When the number of measuring points is sparse, it is difficult to achieve accurate damage localization at the floor level in super high-rise buildings. Therefore, there is an urgent need for a method that can achieve accurate damage localization on real structures with a small number of sensors. Summary of the Invention One of the technical problems to be solved by this invention is the low accuracy of structural damage positioning due to constraints in real-world engineering conditions.

[0004] To address the aforementioned technical problems, in a first aspect, embodiments of this disclosure provide a method for determining structural damage. The method includes: acquiring a non-destructive reference mode shape of a target structure at a first set of preset measurement points; when the state of the target structure is unknown, acquiring a first measurement mode shape at the first set of preset measurement points, and calculating the first mode shape curvature of the first measurement mode shape and the non-destructive reference mode shape at the first set of preset measurement points; determining an initial damage interval from the first set of preset measurement points based on the first mode shape curvature; acquiring a second measurement mode shape at a second set of preset measurement points within the initial damage interval, and calculating the second mode shape curvature of the second measurement mode shape and the non-destructive reference mode shape at corresponding positions, wherein the distribution density of the second set of preset measurement points within the initial damage interval is higher than the distribution density of the first set of preset measurement points on the target structure; and determining the target damage location from the initial damage interval based on the second mode shape curvature.

[0005] Optionally, obtaining the non-destructive reference vibration mode of the target structure at the first set of preset measurement points includes: obtaining the measured vibration mode of the target structure at the first set of preset measurement points; performing modal calculations on the initial finite element model of the target structure to obtain the finite element theoretical vibration mode of the target structure; and performing data fitting between the measured vibration mode and the finite element theoretical vibration mode to obtain the non-destructive reference vibration mode.

[0006] Optionally, determining the initial damage interval from the first set of preset measuring points based on the first mode shape curvature includes: determining the first mode shape curvature ratio and the first mode shape curvature difference based on the first mode shape curvature, wherein, for the first set of preset measuring points... k At each measuring point, the curvature of the first mode shape... Based on the central difference method, the following formula is used for calculation:

[0007] in, , , These represent three adjacent measuring points arranged along the target structure in the first set of preset measuring points. k -1, k , k +1) of i Mode displacement, Indicates the first k The first measuring point i Mode curvature, h This represents the distance between adjacent measuring points in the first set of preset measuring points; based on the first mode curvature ratio and the first mode curvature difference, the initial damage interval is determined from the first set of preset measuring points.

[0008] Optionally, determining the initial damage interval from the first set of preset measurement points based on the first mode shape curvature ratio and the first mode shape curvature difference includes: determining the initial damage interval from the first set of preset measurement points when there is a measurement point in the first set of preset measurement points that meets the following conditions: the first mode shape curvature ratio of the measurement point is greater than a first preset ratio threshold, and the first mode shape curvature difference of the measurement point is the maximum value of the measurement point in the local area formed by the upper and lower adjacent measurement points, wherein the initial damage interval is determined by the distribution of all measurement points that meet the conditions.

[0009] Optionally, determining the target damage location from the initial damage interval based on the second mode curvature includes: determining a second mode curvature difference based on the second mode curvature; and determining the target damage location from the initial damage interval based on the second mode curvature difference.

[0010] Optionally, determining the target damage location from the initial damage interval based on the second mode curvature difference includes: determining the target damage location from the second set of preset measuring points when there is a measuring point in the second set of preset measuring points that satisfies the following condition: the second mode curvature difference of the measuring point is the maximum value of the measuring point in the local area formed by the upper and lower adjacent measuring points, wherein the target damage location is determined by the distribution of all measuring points that satisfy the condition.

[0011] Optionally, obtaining the second measurement mode shape at the second set of preset measurement points within the initial damage interval includes: performing dynamic testing on the second set of preset measurement points to obtain the second measurement mode shape, wherein the second set of preset measurement points is arranged to cover each structural unit within the initial damage interval.

[0012] Optionally, the non-destructive reference mode shape, the first measurement mode shape, and the second measurement mode shape are all overall X-direction translational mode shapes of the target structure measured at the core tube position.

[0013] Secondly, embodiments of the present invention provide a processor, wherein the program, when run, is used to execute any of the structural damage determination methods described above.

[0014] Thirdly, embodiments of the present invention provide a computer program product, including a computer program that, when executed by a processor, implements any of the structural damage determination methods described above.

[0015] The above technical solution detects structural damage by first obtaining the non-destructive reference mode shape at a first set of preset measuring points. Then, when the structural state is unknown, a first measured mode shape is obtained at the first set of preset measuring points, and its curvature at the first set of preset measuring points is calculated, along with that of the non-destructive reference mode shape. Based on the curvature of the first mode shape, an initial damage interval is determined from the first set of preset measuring points. Subsequently, a second measured mode shape is obtained at a second set of preset measuring points within this interval, and its curvature at the corresponding position is calculated, along with that of the non-destructive reference mode shape. Finally, based on the curvature of the second mode shape, the target damage location is determined from the initial damage interval. Since the target damage location is obtained through a two-step method of initially locating the damage interval and then precisely locating it within the interval, precise location of the damaged floor is achieved, thus solving the technical problem of low structural damage location accuracy caused by constraints of real-world engineering conditions in related technologies.

[0016] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic flowchart of a structural damage determination method provided in an embodiment of the present invention; Figure 2 This is a three-dimensional finite element model of a super high-rise building provided in an embodiment of the present invention; Figure 3 This is a floor plan of a super high-rise building tower provided in an embodiment of the present invention; Figure 4 In the figure, a and b are comparison diagrams of the first-order X-direction translational fitting mode shape, the finite element model mode shape, and the reference mode shape provided in the embodiment of the present invention; Figure 5 In the figure, a and b are comparison diagrams of the second-order X-direction translational fitting mode shape, the finite element model mode shape and the reference mode shape provided in the embodiment of the present invention; Figure 6 In the figure, a and b are comparison diagrams of the third-order X-direction translational fitting mode shape, the finite element model mode shape and the reference mode shape provided in the embodiment of the present invention; Figure 7 In the above, a, b, and c are respectively the comparison diagrams of the first-order X-direction translational fitting mode shape and the difference between the finite element model mode shape and the reference mode shape provided in the embodiments of the present invention; the comparison diagram of the second-order X-direction translational fitting mode shape and the difference between the finite element model mode shape and the reference mode shape; and the comparison diagram of the third-order X-direction translational fitting mode shape and the difference between the finite element model mode shape and the reference mode shape. Figure 8 In the figures, a and b are respectively the first-order mode curvature difference diagram and the first-order mode curvature ratio diagram for working condition 1 provided in the embodiments of the present invention; Figure 9 In the figure, a and b are respectively the second-order mode curvature difference diagram and the second-order mode curvature ratio diagram of working condition 1 provided in the embodiment of the present invention; Figure 10 In the figures, a and b are respectively the third-order mode curvature difference diagram and the third-order mode curvature ratio diagram for working condition 1 provided in the embodiment of the present invention; Figure 11 In the figure, a and b are respectively the first-order mode curvature difference diagram and the first-order mode curvature ratio diagram of working condition 2 provided in the embodiment of the present invention; Figure 12 In the figure, a and b are respectively the second-order mode curvature difference diagram and the second-order mode curvature ratio diagram of working condition 2 provided in the embodiment of the present invention; Figure 13 In the figure, a and b are respectively the third-order mode curvature difference diagram and the third-order mode curvature ratio diagram of working condition 2 provided in the embodiment of the present invention; Figure 14In the above, a and b are the secondary test vibration mode diagrams for working condition 1 and working condition 2, respectively, provided in the embodiments of the present invention. Figure 15 In the figures a, b, and c, respectively, they are comparison diagrams of the first-order mode curvature and the first-order undamaged mode curvature, the second-order mode curvature and the second-order undamaged mode curvature, and the third-order mode curvature and the third-order undamaged mode curvature provided in the embodiments of the present invention for working condition 1. Figure 16 a, b, and c in the figure are comparison diagrams of the differences between the first-order, second-order, and third-order mode curvatures and the non-destructive reference mode curvatures of working condition 1 provided in the embodiment of the present invention. Figure 17 In the figure, a and b are comparison diagrams of the first-order mode curvature and the non-destructive reference mode curvature values ​​of working condition 2 provided in the embodiment of the present invention; Figure 18 In the figure, a and b are comparison diagrams of the second-order mode curvature and the non-destructive reference mode curvature values ​​of working condition 2 provided in the embodiment of the present invention; Figure 19 In the figure, a and b are comparison diagrams of the third-order mode curvature and the non-destructive reference mode curvature values ​​of working condition 2 provided in the embodiment of the present invention, respectively. Figure 20 In the figure, a and b are comparison diagrams of the difference between the first-order mode curvature and the non-destructive reference mode curvature provided in the embodiment of the present invention under working condition 2. Figure 21 In the figure, a and b are comparison diagrams of the difference between the curvature of the second-order mode shape and the curvature of the non-destructive reference mode shape in working condition 2 provided in the embodiment of the present invention; Figure 22 In the figure, a and b are comparison diagrams of the difference between the curvature of the third mode shape and the curvature of the non-destructive reference mode shape in working condition 2 provided in the embodiment of the present invention. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0019] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0020] The current methods used for structural damage localization mainly address the following issues: (1) Damage identification methods based on modal vibration mode related indices include modal vibration mode curvature index, modal flexibility curvature index, and superimposed curvature mode change rate index, flexibility difference curvature index, etc. These methods generally do not rely on accurate structural finite element models. They identify damage by comparing indices in the undamaged state and the damaged state. However, the identification accuracy of this type of method is affected by the number of measurement points. When the measurement points are sparse, they often cannot locate the accurate floor.

[0021] (2) Damage identification methods based on time-domain indices include response statistical moment indices, covariance function indices, cross-correlation function indices, etc. This type of method omits the process of modal identification of the monitoring data of the structure, and like the modal vibration mode related indices, it does not rely on an accurate structural finite element model. However, the identification accuracy is also affected by the number of measurement points.

[0022] (3) Damage identification methods based on finite element model correction: Damage identification is performed by adjusting the stiffness matrix of the structural finite element model to minimize the residual between the output and observation quantities. Currently, finite element model correction methods generally use the elastic modulus and cross-sectional dimensions of the structural material as correction indicators. By constructing multiple objective functions and using multiple iterative algorithms, different damage identification methods are generated. These methods have clear physical meanings, but the number of correction parameters is generally no greater than the number of measurement points. Therefore, there are limitations on the complexity of the finite element model and certain requirements on the arrangement of measurement points.

[0023] Since the accuracy of the above three methods is affected by the number of measuring points, locating damage to a specific floor presents certain difficulties or requirements. For these reasons, structural damage localization suffers from low accuracy, an excessive number of measuring points, and high costs. This invention provides a method for determining structural damage. Figure 1 This is a flowchart illustrating a method for determining structural damage according to an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes steps S102 to S110.

[0024] Step S102: Obtain the non-destructive reference vibration mode of the target structure at the first set of preset measurement points.

[0025] For the above steps, the target structure can be a reference finite element model used to simulate and replace the structure of a real, non-destructive supertall building. Assuming the target structure is a 71-story frame-core tube structure, the first set of preset measuring points can be 11 measuring points at the corners of the core tube on different floors of the supertall building, such as floors 71, 64, 57, 50, 43, 36, 29, 22, 15, 8, and 1. The step S102, "obtaining the non-destructive reference vibration mode of the target structure at the first set of preset measuring points," mainly aims to establish a high-precision, global non-destructive reference vibration mode for subsequent damage identification.

[0026] As an optional implementation method, a lossless reference mode shape can be obtained through data fitting. The specific process is as follows: by obtaining the measured mode shapes of the target structure at the first set of preset measurement points, modal calculations are performed on the initial finite element model of the target structure to obtain the theoretical finite element mode shape; finally, based on the measured mode shape and the theoretical finite element mode shape, a lossless reference mode shape is obtained through a data fitting algorithm. The fitting steps are as follows: For the target structure, its dynamic equilibrium equation can be expressed as:

[0027] in[ M [ is the mass matrix of the target structure, [ C ] is the damping matrix of the target structure, [ K ] is the stiffness matrix of the target structure, { }、{ }、{ u} represents the time-varying acceleration, velocity, and displacement of the structure in each degree of freedom, respectively. p (t)} represents external incentives.

[0028] The target structure is a low-damped structure, and the effect of damping on its dynamic characteristics is often negligible. Therefore, the damping matrix can be ignored in modal analysis. When there is no external load, the above equation becomes the equation for undamped free vibration, expressed as:

[0029] in This is the characteristic value of the structure, i.e., the square of the structure's natural circular frequency. This represents the characteristic vector of the structure, i.e., the mode shape.

[0030] For the above equations, their eigenvectors form a basis of the vector space, and any vector can be expressed as a linear combination of this basis. When the stiffness matrix [K] and mass matrix [M] of the structure undergo small changes or when there are errors in the finite element modeling, the changes or errors in their eigenvalues ​​and eigenvectors can be expressed as a linear combination of the eigenvectors of the original matrix, that is:

[0031] in For the first i The change in the first mode shape, n The number of modal shapes involved in the calculation. For the first k The participation factors of the modal shapes involved in the calculation. For the first k The modal shapes involved in the calculation.

[0032] In the above steps, let The error between the measured vibration mode and the vibration mode calculated by the finite element method (the theoretical vibration mode of the finite element method). For finite element method (FEM) calculation of mode shapes. For the first... i For mode shapes, the above equations can be transformed into linear equations:

[0033] in[ A ]= ,Depend on n It consists of finite element calculated mode shape vectors at nodes that are the same as the measured mode shape. x}={ } T , indicating by n Participation coefficient A column vector composed of [variables]. b}= , represents the error vector between the finite element calculation and the measured vibration mode at the same node.

[0034] When the number of measured nodes is greater than or equal to the number of modalities involved in the calculation, this linear equation system is an overdetermined or positive definite equation system, and the column vector of participation coefficients can be obtained by solving its generalized inverse. x}, in a generalized sense, the inverse is:

[0035] After calculating the participation coefficient, the mode shape values ​​of the untested nodes can be obtained through superposition calculation.

[0036] After the above fitting calculation, the non-destructive reference mode shape of the target structure in the non-destructive state can be determined.

[0037] It should be noted that by using the first set of preset measuring points, the vibration mode reference of the target structure in a non-destructive state can be established without setting measuring points in the entire area of ​​the target structure. This reduces the workload of obtaining the initial state vibration mode and is suitable for the detection scenarios of large and complex structures such as super high-rise buildings, laying a reliable foundation for subsequent layered positioning.

[0038] Step S104: When the state of the target structure is unknown, obtain the first measurement mode shape at the first set of preset measurement points, and calculate the first mode shape curvature of the first measurement mode shape and the undamaged reference mode shape at the first set of preset measurement points. The unknown state of the target structure can be either a damaged state or an undamaged state.

[0039] It should be noted that, based on the target structure in the scenario in step S102, the above step S104 is executed. Assuming that the target structure is in a damaged state, such as the elastic modulus or the stiffness of local components deteriorating, for example, the elastic modulus of the 21st layer is reduced by 20%, then the first measured vibration mode of the target structure is obtained at the first set of preset measurement points (71, 64, 57, 50, 43, 36, 29, 22, 15, 8, 1 layers).

[0040] Furthermore, by calculating the curvature of the first measured mode shape and the non-destructive reference mode shape fitted in step S102 at the first set of preset measurement points, the curvature difference between the two can be obtained.

[0041] It should also be noted that by comparing the curvature of the first measured mode shape under unknown conditions with that of the non-destructive reference mode shape, the high sensitivity of mode shape curvature to local damage can be used to quickly locate the differences between structural states, without the need to determine whether the structure is damaged in advance, thus adapting to multi-state detection scenarios.

[0042] Step S106: Based on the curvature of the first mode shape, determine the initial damage range from the first set of preset measurement points.

[0043] It should be noted that, based on the scenario descriptions in the preceding steps, under damage conditions (such as damage on the 21st floor), by observing the curvature data of the first set of sparse measuring points (measuring points on 11 floors), determining the initial damage interval based on the curvature of the first mode shape also includes: (1) Based on the curvature of the first mode, calculate the curvature ratio of the first mode and the curvature difference of the first mode respectively; (2) In the first set of preset measurement points, determine which measurement points have a first mode curvature ratio greater than the first preset ratio threshold. Here, the first preset ratio threshold is 1. Also, determine which measurement points have a first mode curvature difference that is the maximum value in the local area formed by the upper and lower adjacent measurement points. Then, select the measurement points that meet the above conditions to determine the initial damage interval. By analyzing the difference in curvature of the first mode shape, the approximate range of damage was determined, solving the problem of inaccurate positioning of a single, small number of measuring points. This not only provided a basis for subsequent precise positioning but also improved the efficiency of target structure damage detection, while reducing the interference of irrelevant data on subsequent detection and analysis.

[0044] Step S108: Obtain the second measurement mode shape at the second set of preset measurement points within the initial damage range, and calculate the second mode shape curvature at the corresponding position of the second measurement mode shape and the undamaged reference mode shape.

[0045] It should be noted that the second set of preset measuring points are located within the initial damage zone, and have a higher density than the first set. This could involve re-deploying sensor measuring points on all floors within the initial damage zone. The second measurement mode shape is obtained through dynamic testing based on these measuring points. Simultaneously, the curvature of the second mode shape relative to the undamaged reference mode shape is calculated. The curvature of the second mode shape further enhances the sensitivity to damage location, providing strong data support for precise localization.

[0046] Step S110: Determine the target damage location from within the initial damage range based on the second mode curvature.

[0047] It should be noted that, based on the second mode curvature determined through the above steps, the steps for determining the target damage location from the initial damage interval also include the following: (1) Calculate the curvature of the second mode shape and the difference between the curvature of the second mode shape and the non-destructive reference mode shape obtained by fitting; (2) Then, based on the difference between the curvature of the second mode and the curvature of the second mode, the same judgment steps as in step S106 for determining the initial damage interval are performed to determine the target damage location.

[0048] By analyzing the curvature of the second mode shape, the target damage location can be accurately detected, solving the problem of inaccurate positioning of a small number of initial measuring points. At the same time, the logic for determining structural damage is also executed step by step from "interval locking" to "precise positioning". Furthermore, the high sensitivity of the mode shape curvature combined with the logic of layered positioning further improves the reliability of damage positioning. Through the above steps S102-S110, when determining structural damage, the initial damage range is determined by the curvature of the first mode shape calculated between the first measured mode shape obtained at the first set of preset measuring points and the undamaged reference mode shape. The target damage location is determined by the curvature of the second mode shape calculated between the second measured mode shape obtained at the second set of preset measuring points within the initial damage range and the undamaged reference mode shape. This allows for the rapid locking of the approximate damage range using a small number of measuring points, followed by a focused analysis of the range using dense measuring points. This ensures the accuracy of damage location while avoiding the high cost and low efficiency associated with densely distributed measuring points across the entire area. Consequently, it solves the technical problem of low structural damage location accuracy caused by constraints imposed by real-world engineering conditions in related technologies.

[0049] As an optional embodiment, obtaining the non-destructive reference mode shape of the target structure at the first set of preset measurement points includes: obtaining the measured mode shape of the target structure at the first set of preset measurement points; performing modal calculations on the initial finite element model of the target structure to obtain the finite element theoretical mode shape of the target structure; and performing data fitting between the measured mode shape and the finite element theoretical mode shape to obtain the non-destructive reference mode shape.

[0050] In this embodiment, the measured vibration modes can be obtained from the actual target structure at the selected first set of preset measurement points. An initial finite element model is selected for the target structure. This initial finite element model has errors in actual engineering. After performing modal calculations on the initial finite element model, its corresponding model vibration modes, i.e., the finite element theoretical vibration modes, are obtained. Furthermore, the measured vibration modes and the finite element theoretical vibration modes are fitted to obtain the non-destructive reference vibration modes of the target structure. The following is a specific scenario example to verify the non-destructive reference mode shape calculated in the above steps. Figure 2 A 3D finite element model of a super high-rise building. Figure 3 This is a floor plan of a super high-rise building tower, combined with... Figure 2 As shown Figure 3 As shown, a reference finite element model (target structure) of a super high-rise building and a finite element model with material elastic modulus error (initial finite element model) are selected to verify the above method. Since it is necessary to verify the above fitting method and the non-destructive reference mode shape obtained by fitting, it is necessary to use the selected reference finite element model (target structure) to generate simulated measured data and obtain the reference mode shape. In other words, the reference mode shape is obtained by generating measured data from the target structure.

[0051] First, the X-direction translational vibration modes located at the corners of the core cylinder in layers 71, 64, 57, 50, 43, 36, 29, 22, 15, 8, and 1 of the reference finite element model are extracted as measured vibration modes. The first three vibration modes are then fitted using the method described above. The fitted vibration modes are the first five X-direction translational vibration modes of the finite element model, which contain errors. The fitted vibration modes (non-destructive reference vibration modes) obtained through this step are then compared and analyzed with the vibration modes of the finite element model (initial finite element model) and the reference vibration modes (obtained from measured data generated from the reference finite element model). The results are as follows: Figure 4 a and b in Figure 5 a, b, and Figure 6 The comparison diagrams shown in Figures a and b are as follows.

[0052] Furthermore, the difference between the fitted mode shape, the finite element model mode shape, and the reference mode shape was calculated, as shown in the figure. Figure 7 As shown in a, b, and c, Figure 7 In the figure, 'a' represents a comparison of the first-order X-direction translational fitted mode shape, the mode shape of the finite element model, and the reference mode shape. Figure 7 In the figure, b represents a comparison of the second-order X-direction translational fitted mode shape, the mode shape of the finite element model, and the reference mode shape. Figure 7 In Figure 'c', we see a comparison of the third-order X-direction translational fitted mode shape, the finite element model mode shape, and the reference mode shape. Combining this with the comparison figures shown in Figures 'a', 'b', and 'c' in section 7, the overall difference between the fitted mode shape and the reference mode shape is smaller than the difference between the finite element model mode shape and the reference mode shape.

[0053] As an optional embodiment, determining the initial damage interval from the first set of preset measuring points based on the first mode shape curvature includes: determining the first mode shape curvature ratio and the first mode shape curvature difference based on the first mode shape curvature, wherein, for the first set of preset measuring points... k One measuring point, first mode curvature Based on the central difference method, the following formula is used for calculation:

[0054] in, , , These represent three adjacent measuring points arranged along the target structure in the first set of preset measuring points. k -1, k , k +1) of i Mode displacement, Indicates the first k The first measuring point i Mode curvature, h This indicates the spacing between adjacent measuring points in the first set of preset measuring points; based on the first mode curvature ratio and the first mode curvature difference, the initial damage interval is determined from the first set of preset measuring points.

[0055] In this embodiment, when damage occurs to the target structure, the mode shape curvature (the second derivative of the mode shape) will change. While it's often impossible to place sensors on every floor of a super high-rise structure, when the damage reaches a certain level, the mode shape curvature can still be calculated using a limited number of measurement points, locating the sensor interval where the damage occurred. The first mode shape curvature can be calculated using the formula of the central difference method described above.

[0056] It should be noted that the above calculation steps are performed under the condition that the spacing between measuring points is the same. This is also based on the fact that the actual super high-rise buildings are quite complex. Therefore, the same spacing between measuring points is selected for subsequent steps of damage location and identification.

[0057] Here, the curvature of the first mode shape can also be calculated using the following formula when the spacing between measuring points is not the same:

[0058] in, Represented as the firstk The height of each measuring point.

[0059] As an optional embodiment, determining the initial damage interval from the first set of preset measurement points based on the first mode curvature ratio and the first mode curvature difference includes: when there is a measurement point in the first set of preset measurement points that meets the following conditions, the initial damage interval is determined from the first set of preset measurement points: the first mode curvature ratio of the measurement point is greater than the first preset ratio threshold, and the first mode curvature difference of the measurement point is the maximum value of the measurement point in the local area formed by the upper and lower adjacent measurement points, wherein the initial damage interval is determined by the distribution of all measurement points that meet the conditions.

[0060] In this embodiment, the first mode curvature ratio and the first mode curvature difference calculated through the above steps are used. The first preset ratio threshold can be set to 1. In specific scenarios, measurement points with a first mode curvature ratio greater than 1 can be selected, and simultaneously, the first mode curvature difference corresponding to that measurement point must be the maximum value within the local area formed by the upper and lower adjacent measurement points. The initial damage interval is then determined from the first set of preset measurement points. The detailed process of determining the initial damage interval is explained using the following scenario example: First, assume two damage conditions are set on the benchmark finite element model (target structure): (1) the elastic modulus of the core tube concrete material of the 21st floor of the benchmark finite element model of the super high-rise building decreases by 20%; (2) the elastic modulus of the core tube concrete material of the 21st and 58th floors decreases by 20%. The X-direction translational vibration modes located at the corners of the core tube of the 71st, 64th, 57th, 50th, 43rd, 36th, 29th, 22nd, 15th, 8th and 1st floors of the benchmark finite element model are still extracted to calculate the mode curvature. The following is a classification of the damage conditions: For operating condition 1, the mode curvature calculated using the above method is the first mode curvature. Then, the curvature difference and curvature ratio between this first mode curvature and the curvature of the non-destructive mode (non-destructive reference mode) are determined, yielding the lower-order intelligent mode curvature difference and mode curvature ratio, such as... Figure 8 The comparison diagrams shown in a and b are as follows. Figure 8 In the diagram, 'a' represents the curvature difference of the first mode shape under operating condition 1. Figure 8 In the diagram, 'b' represents the first-order mode curvature ratio for operating condition 1, as shown below. Figure 9 The comparison diagrams shown in a and b are as follows. Figure 9 In the diagram, 'a' represents the curvature difference of the second-order mode shape under operating condition 1. Figure 9 In the diagram, 'b' represents the curvature ratio of the second mode shape under load condition 1, as shown below. Figure 10 The comparison diagrams shown in a and b are as follows. Figure 10 In the diagram, 'a' represents the curvature difference of the third mode shape under operating condition 1. Figure 10 In the diagram, 'b' represents the curvature ratio of the third mode shape under load condition 1. This is achieved by combining... Figure 8 , Figure 9 and Figure 10 It can be observed that the ratio of the mode curvature near the damaged location to the undamaged mode curvature is greater than 1, and the difference is a local extremum. Therefore, based on these two characteristics, the range of damage can be determined by combining multiple modes. In this case, the initial damage range is located in the 15-29th floor.

[0061] For operating condition 2, the mode curvature calculated using the above method is the first mode curvature. Then, the curvature difference and curvature ratio between this first mode curvature and the curvature of the undamaged mode (undamaged reference mode) are determined, resulting in the following: Figure 11 , Figure 12 and Figure 13 As shown, where, Figure 11 In the diagram, 'a' represents the curvature difference of the first mode shape under operating condition 2. Figure 11 In the diagram, b represents the curvature ratio of the first mode shape under load condition 2. Figure 12 In the diagram, 'a' represents the curvature difference of the second-order mode shape under operating condition 2. Figure 12 In the diagram, b represents the curvature ratio of the second mode shape under load condition 2. Figure 13 The curvature difference diagram of the third mode shape in condition a, 2. Figure 13 In the diagram, 'b' represents the curvature ratio of the third mode shape under load condition 2. Combined with... Figure 11 , Figure 12 and Figure 13 As shown, the initial damage range of working condition 2 is located in layers 15-29 and layers 50-64.

[0062] As an optional embodiment, determining the target damage location from the initial damage interval based on the second mode curvature includes: determining the second mode curvature difference based on the second mode curvature; and determining the target damage location from the initial damage interval based on the second mode curvature difference.

[0063] In this embodiment, based on the two damage conditions set in the previous step, the initial damage intervals are determined to be floors 15-29 and 50-64. However, for super high-rise buildings, simply locating the damage interval is insufficient, as the sensor spacing in super high-rise buildings often reaches tens of meters, which is insufficient to meet the requirements of structural performance evaluation. Therefore, sensors are deployed on all floors within the initial damage intervals of floors 15-29 and 50-64 to conduct dynamic tests, obtaining the modal shapes of all floors, i.e., the second measurement mode shapes obtained at the second preset measurement points. Under the corresponding two damage conditions, Figure 14 In the figure, a and b are the secondary test vibration mode diagrams of working condition 1 and working condition 2 provided in the embodiments of the present invention, respectively.

[0064] Furthermore, after obtaining the modal vibration modes of all floors within the damaged range of the super high-rise building after testing, the curvature of the modal vibration modes corresponding to all floors within the initial damaged range is calculated to obtain the curvature of the second mode, which is then compared with the curvature of the fitted undamaged reference mode. Under the corresponding two damage conditions, Figure 15 In the figures a, b, and c, respectively, they are comparison diagrams of the first-order mode curvature and the first-order undamaged mode curvature, the second-order mode curvature and the second-order undamaged mode curvature, and the third-order mode curvature and the third-order undamaged mode curvature provided in the embodiments of the present invention for working condition 1.

[0065] Furthermore, using the modal curvatures obtained above, the difference between the modal curvatures of operating conditions 1 and 2 and the modal curvatures of the non-destructive reference mode (the second modal curvature difference) is calculated respectively. Figure 16 In the figures, a, b, and c are comparison diagrams of the differences between the first-order, second-order, and third-order mode curvatures and the non-destructive reference mode curvatures of working condition 1 provided in the embodiments of the present invention. Combined with... Figure 15 and Figure 16 As can be seen, the damage in working condition 1 is located between the 20th and 21st floors.

[0066] For scenario 2, which assumes a 20% reduction in the elastic modulus of the core tube concrete material on floors 21 and 58, it is necessary to calculate the low-order curvature values ​​and low-order curvature differences separately. These values ​​are then compared with the curvature values ​​and curvature differences corresponding to the non-destructive reference mode shape. The resulting curvature value comparison diagram is shown below. Figure 17 , Figure 18 , Figure 19 As shown in the figure, a comparison chart of the curvature values ​​measured at the 21st and 58th layers is provided. Figure 17 In the figures, a and b are comparison diagrams of the first-order mode curvature and the non-destructive reference mode curvature values ​​for working condition 2 provided in the embodiments of the present invention; as shown... Figure 18 In the figures, a and b are comparison diagrams of the second-order mode curvature and the non-destructive reference mode curvature values ​​for working condition 2 provided in the embodiments of the present invention; as shown... Figure 19 In the figures, 'a' and 'b' are comparison diagrams of the curvature values ​​of the third-order mode shape and the non-destructive reference mode shape under working condition 2 provided in the embodiment of the present invention. Further, the obtained curvature difference comparison diagram is shown below. Figure 20 , Figure 21 and Figure 22 As shown in the figure, the comparison chart of the curvature difference measured at the 21st and 58th layers is as follows. Figure 20 In the figures, 'a' and 'b' are comparison diagrams of the difference between the first-order mode curvature and the non-destructive reference mode curvature provided in the embodiment of the present invention for working condition 2; as shown... Figure 21 In the figures, 'a' and 'b' are comparison diagrams of the difference between the curvature of the second-order mode shape and the curvature of the non-destructive reference mode shape in working condition 2 provided in the embodiments of the present invention; as shown... Figure 22In the figures, 'a' and 'b' are comparison diagrams of the difference between the curvature of the third-order mode shape and the curvature of the non-destructive reference mode shape under working condition 2 provided in the embodiments of the present invention. Combined with... Figure 20 , Figure 21 and Figure 22 As can be seen, the damage in working condition 2 is located between the 20th and 21st floors and between the 57th and 58th floors.

[0067] It should be noted that after locating the specific floor where the damage occurred, a detailed inspection of the structure of that area should be conducted to find the exact location of the damage.

[0068] As an optional embodiment, determining the target damage location from the initial damage interval based on the second mode curvature difference includes: when there is a measuring point in the second set of preset measuring points that meets the following condition, the target damage location is determined from the second set of preset measuring points: the second mode curvature difference of the measuring point is the maximum value of the measuring point in the local area formed by the upper and lower adjacent measuring points, wherein the target damage location is determined by the distribution of all measuring points that meet the condition.

[0069] In this embodiment, during the determination of the target damage location, certain conditions are first set for the calculated second mode curvature difference value. For example, the curvature difference is the maximum value within the region of adjacent measuring points above and below its measuring point, which is then used as the second mode curvature difference value that meets the conditions within the second set of preset measuring points. Based on the second mode curvature difference value selected according to the above conditions, the target damage location is determined.

[0070] As an optional embodiment, obtaining the second measurement mode shape at the second set of preset measurement points within the initial damage range includes: performing dynamic testing on the second set of preset measurement points to obtain the second measurement mode shape, wherein the second set of preset measurement points is arranged to cover each structural unit within the initial damage range.

[0071] In this embodiment, within the initially determined initial damage range, a second set of preset measuring points are arranged, requiring each independent structural unit to cover at least one measuring point. At the same time, dynamic response data is collected from the second set of preset measuring points using dynamic characteristic testing. Finally, vibration data is calculated through modal recognition, which yields the second measured vibration mode.

[0072] It should be noted that arranging measurement points covering the initial damage area can not only reduce the testing workload in non-critical detection areas, but also extract damage-related structural features more accurately.

[0073] As an optional embodiment, the non-destructive reference mode shape, the first measurement mode shape, and the second measurement mode shape are all overall X-direction translational mode shapes of the target structure measured at the core tube position. In this embodiment, the non-destructive reference mode shape, the first measurement mode shape, and the second measurement mode shape are all uniformly selected as the X-direction translational mode shape of the core tube of the target structure. That is, all three are the modal forms when the core tube vibrates in translational vibration along the X-axis direction, ensuring that the subsequent calculation of the mode shape curvature ratio and curvature difference is based on the modal data of the same vibration direction and the same key structural component.

[0074] It should be noted that the X-direction translational vibration mode in the target structure is more sensitive to structural damage and can quickly capture the changes in modal parameters caused by damage, further improving the ability to locate structural damage.

[0075] The advantages and technical effects of the present invention are as follows: (1) By comparing the curvature between two non-destructive reference mode shapes and the measured mode shape, the initial damage range is accurately located, which improves the accuracy of structural damage location.

[0076] (2) By fully covering the sensor unit of the structure at the second preset measurement point in the initial damage range, the dynamic characteristics of the structure are tested, providing complete data support for the accurate location of structural damage. At the same time, the high-density full-coverage measurement points can refine the spatial sampling accuracy of the mode shape data, making the sudden change in mode shape curvature caused by damage more significant, solving the problem of unclear damage location under sparse measurement points, and greatly improving the positioning accuracy.

[0077] (3) By uniformly selecting the translational vibration mode in the X direction of the structure, the vibration mode in this direction is significantly more sensitive to structural damage in the X direction than the vibration mode in other directions, and can more keenly capture the changes in modal parameters after structural damage.

[0078] (4) By combining the fitting method of “measured mode shape + finite element theoretical mode shape”, a non-destructive reference mode shape is constructed, which effectively avoids the deviation between the pure theoretical model and the actual structure and the noise interference of single measured data, and significantly improves the reliability and accuracy of the reference mode shape.

[0079] This invention provides a processor for running a program, wherein the program is executed to perform: the structural damage determination method as described above; and / or the structural damage determination method as described above.

[0080] The present invention also provides a computer program product that, when executed on a data processing device, is adapted to perform a program for initializing the steps described above.

[0081] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0082] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0083] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0084] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0085] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0086] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0087] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0088] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0089] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for determining structural damage, characterized in that, include: Obtain the non-destructive reference vibration mode of the target structure at the first set of preset measurement points; When the state of the target structure is unknown, a first measurement mode shape is obtained at the first set of preset measurement points, and the first mode shape curvature of the first measurement mode shape and the non-destructive reference mode shape at the first set of preset measurement points is calculated. Based on the curvature of the first mode shape, the initial damage range is determined from the first set of preset measuring points; A second measurement mode shape is obtained at a second set of preset measurement points within the initial damage range, and the curvature of the second measurement mode shape and the non-destructive reference mode shape at corresponding positions is calculated. The distribution density of the second set of preset measurement points within the initial damage range is higher than the distribution density of the first set of preset measurement points on the target structure. Based on the second mode curvature, the target damage location is determined from the initial damage interval.

2. The method according to claim 1, characterized in that, The process of obtaining the non-destructive reference vibration mode of the target structure at the first set of preset measurement points includes: Obtain the measured vibration mode of the target structure at the first set of preset measurement points; Modal operations are performed on the initial finite element model of the target structure to obtain the theoretical finite element mode shape of the target structure. The measured vibration mode and the finite element theoretical vibration mode are fitted together to obtain the non-destructive reference vibration mode.

3. The method according to claim 1, characterized in that, The determination of the initial damage interval from the first set of preset measuring points based on the first mode shape curvature includes: Based on the curvature of the first mode shape, the curvature ratio of the first mode shape and the curvature difference of the first mode shape are determined, wherein, for the first set of preset measuring points... k At each measuring point, the curvature of the first mode shape... Based on the central difference method, the following formula is used for calculation: in, , , These represent three adjacent measuring points arranged along the target structure in the first set of preset measuring points. k -1, k , k +1) of i Mode displacement, Indicates the first k The first measuring point i Mode curvature, h This indicates the distance between adjacent measuring points in the first set of preset measuring points; Based on the first mode shape curvature ratio and the first mode shape curvature difference, the initial damage interval is determined from the first set of preset measuring points.

4. The method according to claim 3, characterized in that, The determination of the initial damage interval from the first set of preset measuring points based on the first mode shape curvature ratio and the first mode shape curvature difference includes: When there is a measuring point in the first set of preset measuring points that meets the following conditions, the initial damage interval is determined from the first set of preset measuring points: The first mode curvature ratio of the measuring point is greater than a first preset ratio threshold, and the first mode curvature difference of the measuring point is the maximum value of the measuring point in the local area formed by the upper and lower adjacent measuring points, wherein the initial damage interval is determined by the distribution of all measuring points that meet the conditions.

5. The method according to claim 1, characterized in that, Determining the target damage location from the initial damage interval based on the second mode curvature includes: Based on the curvature of the second mode shape, determine the curvature difference of the second mode shape; The target damage location is determined from the initial damage interval based on the second mode curvature difference.

6. The method according to claim 5, characterized in that, Determining the target damage location from the initial damage interval based on the second mode curvature difference includes: The target damage location is determined from the second set of preset measuring points when there is a measuring point in the second set that meets the following conditions: The second mode curvature difference of the measuring point is the maximum value of the measuring point in the local area formed by the upper and lower adjacent measuring points, wherein the target damage location is determined by the distribution of all measuring points that satisfy the condition.

7. The method according to claim 1, characterized in that, The step of obtaining the second measurement mode shape at the second set of preset measurement points within the initial damage range includes: Dynamic tests are performed on the second set of preset measuring points to obtain the second measurement mode shape, wherein the second set of preset measuring points are arranged to cover each structural unit within the initial damage range.

8. The method according to claim 1, characterized in that, The non-destructive reference mode shape, the first measurement mode shape, and the second measurement mode shape are all overall X-direction translational mode shapes of the target structure measured at the core tube position.

9. A processor, characterized in that, For running a program, wherein the program is run to perform: the structural damage determination method as described in any one of claims 1 to 8.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the structural damage determination method according to any one of claims 1 to 8.

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