Bridge evaluation method and system based on steady-state excitation

Abstract

A bridge evaluation method and system based on steady-state excitation, the method comprising: under the current working condition, determining the excitation frequency and excitation amplitude according to the first parameter of the target mode and the excitation mass, and applying steady-state excitation to the bridge; calculating the second parameter of the target mode according to the excitation mass, the excitation amplitude, and the bridge structure data during and after the excitation; modifying the basic finite element model in combination with the current bridge component parameter and the second parameter of the target mode; and evaluating the bearing capacity of the bridge by using the calculation result of the modified finite element model. By applying steady-state excitation to the bridge, the bridge produces stable single-mode vibration, which can effectively improve the calculation accuracy of the second parameter of the target mode, further improve the modification accuracy of the finite element model, make the calculation result of the modified finite element model more accurate, and thus improve the accuracy of the bridge evaluation result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge detection, in particular to a bridge evaluation method and system based on steady-state excitation. BACKGROUND

[0002] As a crucial hub in the transportation network, the cross-river bridge plays an indispensable role in the national economy and social development. However, due to its long-term exposure to complex natural environment and continuous traffic load, as well as the gradual aging of the structure over time, the structural performance will inevitably change. In order to ensure that the cross-river bridge is always in a safe and reliable operating state, it is crucial to carry out regular comprehensive and accurate detection and evaluation work, and load test is one of the most effective detection methods.

[0003] In traditional bridge static load tests, deploying a large number of heavy vehicles to simulate actual operating loads not only faces difficulties in vehicle deployment, traffic interference, and bridge closure implementation, but also may affect the structural safety and surrounding traffic, making it difficult to carry out detection work smoothly. Traditional dynamic load tests, when evaluating the dynamic performance of long-span bridges, due to poor excitation effect and low detection accuracy of bridge modal parameters, lead to incomplete and uncontrollable test results, making it difficult to accurately reflect the true dynamic characteristics of the bridge.

[0004] Although most long-span bridges are currently equipped with complete health monitoring systems, which to some extent solve the problem of sensor placement throughout the bridge during traditional bridge static and dynamic load tests, and reduce safety risks. Due to the inevitable differences between existing finite element models and the actual state of the bridge, it is necessary to correct them based on the actual response data of the bridge. However, in current bridge evaluation techniques, the bridge response amplitude is small, the frequency components are complex, and the load information is unknown, making it difficult to achieve high-precision correction of the finite element model, resulting in low accuracy of the bridge evaluation results. SUMMARY

[0005] The present application provides a bridge evaluation method and system based on steady-state excitation, which can solve the technical problem of low accuracy of the evaluation results in current cross-river bridge evaluation techniques.

[0006] To achieve the above-mentioned purpose, in a first aspect, the present application provides a bridge evaluation method based on steady-state excitation, the method comprising:

[0007] Under the current working condition, the excitation frequency and excitation amplitude are determined according to the first parameter of the target mode and the excitation mass, and the bridge is subjected to steady-state excitation.

[0008] The second parameter of the target mode is calculated according to the excitation mass, the excitation amplitude, and the bridge structure data during and after the excitation process.

[0009] The base finite element model is corrected according to the current bridge component parameters and the second parameters of the target modal.

[0010] The carrying capacity of the bridge is evaluated according to the calculation result of the corrected finite element model.

[0011] Further, in an embodiment, the first parameters of the target modal are obtained from historical detection data of the bridge, obtained by a bridge health monitoring system, or calculated by the base finite element model.

[0012] Further, in an embodiment, the determination of the excitation frequency and the excitation amplitude according to the first parameters of the target modal and the excitation mass comprises:

[0013] The first parameters of the target modal include a first frequency of the target modal, a first mass of the target modal, a first mode shape of the target modal, a first damping ratio of the target modal, and a first amplitude of the target modal.

[0014] The first frequency of the target modal is taken as the excitation frequency.

[0015] The excitation amplitude is determined according to the excitation mass, the first mass of the target modal, the first mode shape of the target modal, the first damping ratio of the target modal, and the first amplitude of the target modal.

[0016] Further, in an embodiment, the calculation of the second parameters of the target modal according to the excitation mass, the excitation amplitude, and the bridge structure data during the excitation process and after the excitation stops comprises:

[0017] The bridge structure data includes vibration response data after the excitation stops and a steady-state amplitude during the excitation process.

[0018] The second parameters of the target modal include a second frequency of the target modal, a second damping ratio of the target modal, a second mode shape of the target modal, and a second mass of the target modal.

[0019] The second frequency of the target modal is obtained by Fourier transform on the vibration response data.

[0020] The second damping ratio of the target modal is obtained by fitting on the vibration response data.

[0021] The second mode shape of the target modal is obtained by normalization on the steady-state amplitude.

[0022] The second mass of the target modal is calculated according to the second mode shape of the target modal, the second damping ratio of the target modal, the steady-state amplitude, the excitation mass, and the excitation amplitude.

[0023] Further, in an embodiment, the vibration response data includes acceleration response data, velocity response data, or displacement response data.

[0024] Further, in an embodiment, the second parameter of the target modal is combined with the current bridge component parameter to correct the basic finite element model, including:

[0025] Sensitivity analysis is performed on the current bridge component parameter to determine the bridge component parameter to be corrected.

[0026] The first parameter of the target modal is calculated using the basic finite element model based on the bridge component parameter to be corrected, and a target function is constructed by combining the second parameter of the target modal.

[0027] The finite element model based on the bridge component parameter to be corrected at the minimum value of the target function value is the corrected finite element model.

[0028] Further, in an embodiment, the calculation result of the corrected finite element model is used to evaluate the carrying capacity of the bridge, including:

[0029] According to the corrected finite element model and the preset bridge load, the bridge component response parameter is calculated;

[0030] According to the calculated bridge component response parameter result and the preset evaluation standard, the carrying capacity of the bridge is evaluated;

[0031] The bridge component response parameter includes deformation of the bridge component, internal force of the bridge component, and strain of the bridge component.

[0032] Further, in an embodiment, the preset bridge load includes static load, dynamic load, environmental load, or combined load of multiple loads.

[0033] In a second aspect, based on the above-mentioned bridge evaluation method based on steady-state excitation, the present application provides a bridge evaluation system based on steady-state excitation, the system comprising:

[0034] The excitation module is used to determine the excitation frequency and the excitation amplitude according to the first parameter of the target modal and the excitation mass under the current working condition, and to apply steady-state excitation to the bridge.

[0035] The calculation module is used to calculate the second parameter of the target modal according to the excitation mass, the excitation amplitude, and the bridge structure data during and after the excitation.

[0036] The correction module is used to correct the basic finite element model by combining the current bridge component parameter and the second parameter of the target modal.

[0037] The evaluation module is used to evaluate the carrying capacity of the bridge using the calculation result of the corrected finite element model.

[0038] Further, in an embodiment, the system further comprises a sensitivity module configured to perform a sensitivity analysis on the current bridge member parameters in the correction module.

[0039] The technical scheme provided by the embodiments of the present application has the beneficial effects of:

[0040] The embodiments of the present application determine the exciting frequency and the exciting amplitude according to the first parameter of the target modal and the exciting mass under the current working condition, and apply steady-state excitation to the bridge; calculate the second parameter of the target modal according to the exciting mass, the exciting amplitude, and the bridge structure data during and after the excitation process; correct the basic finite element model in combination with the current bridge member parameters and the second parameter of the target modal; and evaluate the bearing capacity of the bridge by using the calculation result of the corrected finite element model. By applying steady-state excitation to the bridge, the bridge produces stable single modal vibration, which can effectively improve the calculation accuracy of the second parameter of the target modal when the second parameter of the target modal is calculated by using the bridge structure data during and after the excitation process. Further, the correction accuracy of the finite element model is also improved when the basic finite element model is corrected by using the current bridge member parameters and the second parameter of the target modal, so that the calculation result of the corrected finite element model is more accurate, thereby improving the accuracy of the bridge evaluation result. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The flowchart of the bridge evaluation method based on steady-state excitation of the embodiments of the present application.

[0042] Figure 2 The acceleration response simulation diagram of the embodiments of the present application.

[0043] Figure 3 The block diagram of the bridge evaluation system based on steady-state excitation of the embodiments of the present application. DETAILED DESCRIPTION

[0044] In order to enable personnel in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0045] It should be noted that the present application strictly refers to the requirements of bridge specifications such as the “Highway Bridge Bearing Capacity Detection and Evaluation Regulations” to comprehensively and scientifically evaluate the bearing capacity of the bridge, including:

[0046] (1) Multi-condition analysis and checking: fully analyze and check various conditions of the ultimate limit state and the normal use limit state. Consider the bearing capacity performance of the bridge under different loads and load combinations, different structural stress states, to ensure the comprehensiveness and accuracy of the evaluation results.

[0047] (2) Comprehensive evaluation: comprehensively consider the modal parameters, material properties, historical detection data and finite element model correction results of the bridge, and evaluate the bearing capacity of the bridge according to relevant specifications and standards, to provide important decision basis for the maintenance, repair and management of the bridge.

[0048] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0049] In a first aspect, an embodiment of a bridge evaluation method based on steady-state excitation is provided.

[0050] In the embodiment, referring to FIG. 1, the bridge evaluation method based on steady-state excitation includes: Figure 1

[0051] S1, under the current working condition, determine the excitation frequency and excitation amplitude according to the first parameter of the target mode and the excitation mass, and apply steady-state excitation to the bridge.

[0052] S2, calculate the second parameter of the target mode according to the excitation mass, the excitation amplitude, and the bridge structure data during and after the excitation.

[0053] S3, modify the basic finite element model in combination with the current bridge component parameters and the second parameter of the target mode.

[0054] S4, evaluate the bearing capacity of the bridge using the calculation results of the modified finite element model.

[0055] In the embodiment, by applying steady-state excitation to the bridge, the bridge generates stable single modal vibration, and the second parameter of the target mode is calculated using the bridge structure data during and after the excitation, which can significantly improve the accuracy of the second parameter of the target mode. On this basis, the basic finite element model is modified using the current bridge component parameters and the second parameter of the target mode, which further improves the accuracy of the finite element model modification, making the calculation results of the modified finite element model more reliable, thereby effectively improving the accuracy of the bridge evaluation results.

[0056] Further, in an embodiment, the source of the first parameter of the target mode in step S1 includes: obtained from bridge historical detection data, monitored by a bridge health monitoring system, or calculated by a basic finite element model. ​

[0057] In the embodiment, the first parameters of the target modal are obtained by using the existing health monitoring system, historical detection data or a basic finite element model, the excitation efficiency is improved, the bridge structure state can be comprehensively understood, the reliability of the detection result is improved, the number of sensor arrangement and the working difficulty in the detection process are reduced to a certain extent, and the safety risk is reduced.

[0058] Further, in an embodiment, in the step S1, the bridge is subjected to the steady-state excitation by the excitation detection vehicle, and the bridge is divided into multiple working conditions according to the position of the excitation detection vehicle on the main beam of the bridge, and each working condition includes multiple sub-working conditions. In the sub-working condition, the position of the excitation detection vehicle on the main beam of the bridge is fixed, and only the excitation frequency and the excitation amplitude are changed to realize the excitation of each order target modal of the bridge in the sub-working condition.

[0059] In the embodiment, in order to reduce the interference on the normal traffic in the excitation process and the influence of the bridge driving on the excitation effect, the excitation time is selected as a time period with relatively small traffic flow (such as 22:00-04:00), and the excitation place is the emergency lane.

[0060] Further, in an embodiment, in the step S1, the first parameters of the target modal include the first frequency of the target modal, the first mass of the target modal, the first vibration mode of the target modal, the first damping ratio of the target modal and the first amplitude of the target modal. According to the first parameters of the target modal and the excitation mass, the excitation frequency and the excitation amplitude are determined, which specifically includes the following steps:

[0061] S11, the first frequency of the target modal is taken as the excitation frequency.

[0062] S12, according to the excitation mass, the first mass of the target modal, the first vibration mode of the target modal, the first damping ratio of the target modal and the first amplitude of the target modal, the excitation amplitude is determined, and the excitation mass is the mass of the active mass block of the exciter.

[0063] In the embodiment, according to the first parameters of the target modal and the excitation mass, the excitation frequency and the excitation amplitude are determined, and the bridge is subjected to the steady-state excitation according to the excitation frequency and the excitation amplitude, so that the bridge produces stable single modal vibration.

[0064] Further, in an embodiment, the step S12 can derive the calculation formula of the excitation amplitude by the motion equation of the nth order modal of the bridge under the excitation, and the excitation amplitude is calculated by combining the first amplitude of the target modal, which is specifically as follows:

[0065] The motion equation of the nth order modal of the bridge under the excitation is subjected to Laplace transformation to obtain the steady-state response equation of the nth order target modal of the bridge.

[0066] The motion equation of the nth mode of the bridge under the action of the exciting force is:

[0067] ,

[0068] wherein, represents the mass of the nth target mode of the bridge, represents the damping of the nth target mode of the bridge, represents the stiffness of the nth target mode of the bridge, represents the exciting mass, represents the exciting amplitude, represents the exciting frequency, represents the generalized coordinate of the nth target mode of the bridge, represents the mode shape of the nth target mode of the bridge at the position of the bridge where the excitation is located.

[0069] The equation of the steady-state response of the nth target mode of the bridge is:

[0070] ,

[0071] wherein, represents the ratio of the exciting frequency to the frequency of the nth target mode of the bridge, represents the damping ratio of the nth target mode of the bridge.

[0072] According to the equation of the steady-state response of the nth target mode of the bridge and the mode shape of the nth target mode of the bridge, the equation of the amplitude of the nth target mode of the bridge at the spanwise position x of the main girder of the bridge is obtained, which is as follows:

[0073] ,

[0074] wherein, represents the mode shape of the nth target mode of the bridge, represents the steady-state response of the nth target mode of the bridge.

[0075] Since the target mode frequency of the nth target mode of the bridge is set as the exciting frequency, i.e. , the equation of the amplitude of the nth target mode of the bridge at the spanwise position x of the main girder of the bridge is:

[0076] ,

[0077] wherein, represents the mode shape of the nth target mode of the bridge.

[0078] Further, the calculation formula of the exciting amplitude is obtained, i.e.: ​​​​

[0079] .

[0080] Further, in an embodiment, in the step S2, the second parameters of the target mode are calculated according to the exciting mass, the exciting amplitude, and the bridge structure data during the exciting process and after the exciting stops, including:

[0081] The bridge structure data during the exciting process and after the exciting stops are collected, wherein the bridge structure data includes the vibration response data after the exciting stops and the steady-state amplitude during the exciting process, the vibration response data includes the acceleration response data, the speed response data, or the displacement response data, and the bridge structure data is collected by the bridge health monitoring system, the additional sensors of the excited bridge, and the sensors of the exciting detection vehicle.

[0082] The second parameters of the target mode include the second frequency of the target mode, the second damping ratio of the target mode, the second mode shape of the target mode, and the second mass of the target mode, wherein:

[0083] The second frequency of the target mode is obtained by Fourier transform on the vibration response data, the second damping ratio of the target mode is obtained by fitting on the vibration response data, the second mode shape of the target mode is obtained by normalization on the steady-state amplitude, and the second mass of the target mode is calculated according to the second mode shape of the target mode, the second damping ratio of the target mode, the steady-state amplitude, the exciting mass, and the exciting amplitude.

[0084] Further, in an embodiment, referring to FIG. 2, in the step S2, the second parameters of the target mode are calculated according to the exciting mass, the exciting amplitude, the acceleration response data after the exciting stops, and the steady-state amplitude during the exciting process, including: Figure 2 In the steady-state section in the bridge main beam according to the actual mode shape of the target mode, the steady-state amplitude of the nth order target mode of the bridge main beam at different spanwise positions is normalized according to the following formula to obtain the second mode shape of the target mode:

[0085] Figure 2 ,

[0086] ,

[0087] wherein, represents the amplitude of the nth order target mode of the bridge main beam at the spanwise position x, represents the maximum value of the steady-state amplitude of the nth order target mode of the bridge main beam at different spanwise positions.

[0088] In the steady-state section in the bridge main beam according to the actual mode shape of the target mode, the steady-state amplitude of the nth order target mode of the bridge main beam at different spanwise positions is normalized according to the following formula to obtain the second mode shape of the target mode: Figure 2 ​the free decay stage (i.e. the stage after the excitation stops), performing Fourier transform on the acceleration response data to obtain the second frequency of the target mode, and performing fitting on the acceleration response data to obtain the second damping ratio of the target mode, the fitting formula being:

[0089] ,

[0090] wherein z represents the acceleration response data, z o represents the initial value of the acceleration response data, and t represents time.

[0091] According to the second vibration mode of the target mode, the second damping ratio of the target mode, the steady-state amplitude, the excitation mass and the excitation amplitude, the second mass of the target mode is calculated, and the calculation formula is:

[0092] .

[0093] Further, in an embodiment, in the step S3, the basic finite element model is modified in combination with the current bridge component parameters and the second parameters of the target mode, including:

[0094] S31, sensitivity analysis is performed on the current bridge component parameters to determine the bridge component parameters to be modified, specifically:

[0095] S311, according to the actual technical condition of the bridge and engineering experience, the current bridge component parameters are selected, and the sensitivity of the current bridge component parameters is calculated by using the following formula:

[0096] ,

[0097] wherein, represents the i-th bridge component parameter, represents the bridge component parameter increment, represents the number of bridge component parameters, represents the j-th parameter of the second parameters of the target mode.

[0098] In the embodiment, the bridge component parameters include the elastic modulus, the unit weight, the cross-sectional moment of inertia and the initial stress and the like.

[0099] S312, a preset number of bridge component parameters are selected in the order from high to low sensitivity as the parameters to be modified, and the modification range of the bridge component parameters to be modified is determined.

[0100] The modification range of the bridge component parameters to be modified is: wherein, represents the minimum value of the i-th bridge component parameter, represents the maximum value of the i-th bridge component parameter.

[0101] S32, calculate the first parameter of the target modal by using the basic finite element model based on the bridge component parameter to be corrected, and construct a target function by combining the second parameter of the target modal, in particular:

[0102] S321, sample the bridge component parameter to be corrected by using the Latin hypercube design method, calculate the first parameter of the target modal corresponding to the bridge component parameter to be corrected based on the basic finite element model, constitute a sample set, fit the sample set by using a spatial interpolation algorithm based on a covariance function, construct a Kriging proxy model, and the Kriging proxy model formula is as follows:

[0103]

[0104] wherein, the first parameter matrix of the target modal, the number of the first parameter of the target modal, the regression coefficient, the random process matrix.

[0105] S322, take the residual sum of squares of the first parameter of the target modal calculated by the Kriging proxy model and the second parameter of the target modal calculated in the above step S2 as a target function, and the target function equation is:

[0106]

[0107] wherein, the number of the same type of target modal parameter, the first parameter of the target modal calculated by the Kriging proxy model, the second parameter of the target modal calculated in the above step S2.

[0108] S33, the finite element model based on the bridge component parameter when the target function value is the smallest is the corrected finite element model.

[0109] In the embodiment, through the above steps, a finite element model more in line with the actual bridge state is obtained based on the correction of the bridge component parameter, thereby improving the accuracy and reliability of the model and providing a scientific basis for the health monitoring and maintenance of the bridge. Through the combination of sensitivity analysis and the Kriging proxy model, the accurate correction of the bridge component parameter is effectively realized, and the safety and durability of the bridge structure are ensured.

[0110] Further, in an embodiment, in step S4, the calculation result of the corrected finite element model is used to evaluate the bearing capacity of the bridge, including the steps of:

[0111] ​​S41, calculating bridge component response parameter values according to the modified finite element model and preset bridge loads, wherein the bridge component response parameters include deformation of the bridge component, internal force of the bridge component, and strain of the bridge component, and the preset bridge loads include static loads, dynamic loads, environmental loads, or combined loads of multiple loads.

[0112] S42, evaluating the bridge carrying capacity according to the calculated bridge component response parameter values and preset evaluation criteria.

[0113] In a second aspect, based on the embodiments of the bridge evaluation method based on steady-state excitation described above, an embodiment of a bridge evaluation system based on steady-state excitation is provided. Referring to Figure 3 As shown in the figure, the system includes an excitation module, a calculation module, a modification module, and an evaluation module, specifically:

[0114] The excitation module is configured to determine the excitation frequency and excitation amplitude according to the first parameter of the target mode and the excitation mass under the current working condition, and to apply steady-state excitation to the bridge.

[0115] The calculation module is configured to calculate the second parameter of the target mode according to the excitation mass, the excitation amplitude, and the bridge structure data during and after the excitation.

[0116] The modification module is configured to modify the basic finite element model in combination with the current bridge component parameters and the second parameter of the target mode.

[0117] The evaluation module is configured to evaluate the carrying capacity of the bridge using the calculation results of the modified finite element model.

[0118] Further, in an embodiment, the system further includes a sensitivity module configured to perform sensitivity analysis on the current bridge component parameters in the modification module.

[0119] The present application applies steady-state excitation to the bridge, calculates the target mode parameters using the bridge structure data during and after the excitation, i.e. the response data of the bridge to the steady-state excitation, dynamically modifies the existing bridge finite element model using the parameter data of the target mode of the bridge, and makes the model more consistent with the actual structure state of the bridge. On this basis, the carrying capacity evaluation can more accurately reflect the true carrying capacity of the bridge, provide a reliable basis for bridge maintenance decision-making, and effectively reduce the deviation in the evaluation results caused by the inaccuracy of the current carrying capacity evaluation method. In addition, the data sources of the present application are extensive, such as bridge historical detection data, bridge health monitoring systems, or basic finite element models, and therefore, the comprehensiveness of the data in the bridge evaluation process can be improved, thereby improving the accuracy of the evaluation results.

[0120] It should be noted that the above-mentioned sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages or disadvantages of the embodiments.

[0121] The terms "comprise", "comprising", "include", "including", "have" and "having" in the specification and claims of the present application and the above-described drawings are intended to cover a non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device. The terms "first", "second" and "third" and the like descriptions are used to distinguish different objects, and do not represent the order or limit the types of "first", "second" and "third".

[0122] In the description of the embodiments of the present application, "exemplary", "for example", "for instance" or "such as" are used to represent an example, illustration or description. Any embodiment or design scheme described as "exemplary", "for example" or "for instance" in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. In fact, the words "exemplary", "for example", "for instance" or the like are intended to present the relevant concept in a specific manner.

[0123] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text only describes the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone, in addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0124] In some of the processes described in the embodiments of the present application, a plurality of operations or steps are included in a specific order, but it should be understood that these operations or steps can be executed or executed in parallel without the order in which they appear in the embodiments of the present application, and the sequence number of the operation is only used to distinguish each different operation, and the sequence number itself does not represent any execution order. In addition, these processes can include more or fewer operations, and these operations or steps can be executed in sequence or in parallel, and these operations or steps can be combined.

[0125] Those skilled in the art can clearly understand the above-mentioned embodiment method can be realized by means of software and the necessary general hardware platform, of course, can also be realized by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a plurality of instructions for making a terminal device execute the method described in each embodiment of the present application.

[0126] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A bridge evaluation method based on steady-state excitation, characterized by, The method comprises: In the current working condition, the first parameter of the target mode and the exciting mass are used to determine the exciting frequency and the exciting amplitude, and a steady-state excitation is applied to the bridge; The second parameter of the target mode is calculated according to the exciting mass, the exciting amplitude, and the bridge structure data during and after the excitation; The basic finite element model is corrected by combining the current bridge component parameters and the second parameter of the target mode; The bearing capacity of the bridge is evaluated by using the calculation results of the corrected finite element model; The first parameter of the target mode includes the first frequency of the target mode, the first mass of the target mode, the first mode shape of the target mode, the first damping ratio of the target mode, and the first amplitude of the target mode; The first parameter of the target mode is obtained from the historical detection data of the bridge, the bridge health monitoring system, or the basic finite element model; The second parameter of the target mode includes the second frequency of the target mode, the second damping ratio of the target mode, the second mode shape of the target mode, and the second mass of the target mode.

2. The steady-state excitation-based bridge evaluation method of claim 1, wherein, The first parameter of the target mode includes the first frequency of the target mode, the first mass of the target mode, the first mode shape of the target mode, the first damping ratio of the target mode, and the first amplitude of the target mode; The first frequency of the target mode is used as the exciting frequency; The exciting amplitude is determined according to the exciting mass, the first mass of the target mode, the first mode shape of the target mode, the first damping ratio of the target mode, and the first amplitude of the target mode.

3. The steady-state excitation-based bridge evaluation method of claim 1, wherein, The second parameter of the target mode is calculated according to the exciting mass, the exciting amplitude, and the bridge structure data during and after the excitation; The bridge structure data includes the vibration response data after the excitation is stopped and the steady-state amplitude during the excitation; The second frequency of the target mode is obtained by Fourier transform of the vibration response data; The second damping ratio of the target mode is obtained by fitting the vibration response data; The second mode shape of the target mode is obtained by normalizing the steady-state amplitude; The second mass of the target mode is calculated according to the second mode shape of the target mode, the second damping ratio of the target mode, the steady-state amplitude, the exciting mass, and the exciting amplitude.

4. The steady-state excitation-based bridge evaluation method of claim 3, wherein, The vibration response data includes acceleration response data, velocity response data, or displacement response data.

5. The steady-state excitation-based bridge evaluation method as claimed in claim 1, wherein, The basic finite element model is corrected by combining the current bridge component parameters and the second parameter of the target mode, which comprises: The sensitivity of the current bridge component parameters is analyzed to determine the bridge component parameters to be corrected; The first parameter of the target mode is calculated by using the basic finite element model based on the bridge component parameters to be corrected, and the target function is constructed by combining the second parameter of the target mode; The finite element model based on the bridge component parameters to be corrected at the minimum value of the target function is the corrected finite element model.

6. The steady-state excitation-based bridge evaluation method as claimed in claim 1, wherein, The bearing capacity of the bridge is evaluated by using the calculation results of the corrected finite element model, which comprises: Bridge component response parameters are calculated according to the corrected finite element model and the preset bridge load; The bearing capacity of the bridge is evaluated according to the calculated bridge component response parameters and the preset evaluation standard; The bridge component response parameters include the deformation of the bridge component, the internal force of the bridge component, and the strain of the bridge component.

7. The steady-state excitation-based bridge evaluation method of claim 6, wherein, The preset bridge load includes a static load, a dynamic load, an environmental load, or a combined load of multiple loads.

8. A bridge evaluation system based on the steady-state excitation-based bridge evaluation method according to any one of claims 1 to 7, characterized by The system comprises: a vibration excitation module configured to determine a vibration excitation frequency and a vibration excitation amplitude according to the first parameter of the target mode and the vibration excitation mass in a current working condition, and to apply a steady-state vibration excitation to the bridge; a calculation module configured to calculate the second parameter of the target mode according to the vibration excitation mass, the vibration excitation amplitude, and the bridge structure data during the vibration excitation and after the vibration excitation stops; a correction module configured to correct the basic finite element model in combination with the current bridge component parameter and the second parameter of the target mode; an evaluation module configured to evaluate the bearing capacity of the bridge by using the calculation result of the corrected finite element model.

9. The steady-state excitation-based bridge evaluation system of claim 8, wherein, The system further comprises a sensitivity module configured to perform a sensitivity analysis on the current bridge component parameter in the correction module.

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