Force correction updating iteration hybrid test method and system based on multi-task loading, storage medium and equipment

Abstract

The invention discloses a force correction updating iteration hybrid test method and system based on multi-task loading, a storage medium and equipment, and belongs to the field of structural hybrid test technology application. The method comprises the following steps: establishing a numerical model of a numerical substructure of a prototype structure and a numerical model of a test substructure, solving a first-round motion equation to obtain a loading command, preprocessing the loading command and obtaining test data, establishing an update iteration equation of two force correction model parameters, and updating the force correction model parameters in real time according to the test data of the previous round. Inputting the correction force of the last round, solving the updated motion equation, executing iterative loading, collecting test data, determining whether a convergence index reaches an engineering precision threshold value or not, and if yes, terminating iteration; and if not, circularly updating the model parameters and the command loading process until the convergence index reaches the engineering precision threshold value, and continuously adjusting and improving the parameters of the force correction model so as to approach a better result.

Description

Technical Field

[0001] The present invention specifically relates to a force correction update iterative hybrid test method, system, storage medium and equipment based on multi-task loading, and relates to the technical field of structural hybrid testing. Background Art

[0002] The real-time hybrid testing method, an emerging seismic testing method that combines real-world physical testing with computer numerical simulation, demonstrates unique advantages in the field of structural seismic research. Real-time loading of critical and complex structural locations within a structure with prominent nonlinear characteristics yields accurate test data. Numerical simulations using computer software effectively reduce testing costs and expand the scope of application. By establishing a high-speed data exchange channel, real-time interaction of data between the two can be achieved, meeting the test requirements for velocity and acceleration characteristics of specific specimens. However, this method faces numerous challenges in practical application. Specifically, within the i-th time step, a series of operations must be completed, including solving the equation of motion, transmitting loading instructions, dynamic loading, and data feedback. This places extremely high demands on the system's real-time performance. Delays in the numerical calculation and dynamic loading systems can easily lead to divergence in test results. The complexity of numerical simulations and the stringent boundary coordination conditions make it difficult to ensure real-time data transmission and loading.

[0003] When a structure contains multiple nonlinear components, there are currently two main testing strategies: First, conventional real-time hybrid testing requires simultaneous real-time loading of multiple specimens. However, due to differences in the time delays of the loading systems, loading asynchrony frequently occurs, which can lead to test failure in severe cases. Second, the model updating method selects one nonlinear component as the experimental substructure and the remaining components as numerical substructures. Real-time loading feedback data from the experimental substructure is used to update the constitutive model of the numerical substructure online. However, the performance of the simulated experimental substructure still lags behind that obtained from direct testing, and achieving high real-time synchronization between numerical calculations and physical loading is difficult. Furthermore, the recently proposed real-time hybrid testing method based on multi-task loading does not rigorously calculate and deducible the force correction model parameters, but directly uses the established parameters of the specimen. This practice significantly limits the application of this method to complex structures.

[0004] In response to the problems of low force correction model accuracy and slow iterative convergence in the existing technology, the present invention provides a force correction update iterative hybrid test method, system, storage medium and equipment based on multi-task loading, which improves the test accuracy and convergence efficiency by real-time updating of model parameters and dynamic adjustment of weight coefficients. Summary of the Invention

[0005] In order to solve the problem of divergence of test results caused by low accuracy of the force correction model, the present invention proposes a force correction update iterative hybrid test method based on multi-task loading. The force correction update iterative hybrid test method is to establish a numerical model of the numerical substructure of the prototype structure and a numerical model of the test substructure, solve the first round of motion equations to obtain loading commands, preprocess the loading commands and obtain test data, establish an update iterative equation for the force correction model parameters, update the force correction model parameters in real time according to the previous round of test data, input the previous round of correction force, solve the updated motion equations, execute iterative loading and collect test data, determine whether the convergence index reaches the engineering accuracy threshold, if so, terminate the iteration; if not, cyclically update the model parameters and loading commands until the convergence index reaches the engineering accuracy threshold.

[0006] Preferably, the force correction model parameters include the damping C of the test substructure E , stiffness K E and the weight coefficient λ value.

[0007] Preferably, the force correction update iterative hybrid test method includes:

[0008] S1. Establish numerical models of the numerical substructure of the prototype structure and the numerical model of the test substructure, solve the first round of motion equations to obtain loading commands, including obtaining loading commands for the first round of tests:

[0009] The motion equation can be expressed as:

[0010]

[0011] In the above formula, M, C, and K represent the mass matrix, damping matrix, and stiffness matrix of the numerical substructure, respectively; Respectively represent the time-history acceleration matrix, time-history velocity matrix, and time-history displacement matrix of the numerical substructure in the first round, step i; represents the time-history reaction of the numerical model of the test substructure in the first round; the subscript N represents the numerical substructure; i represents the integration time step; a g,i represents the earthquake acceleration excitation;

[0012] S2. performing time lag compensation on the loading command, and acquiring test data according to the loading command after time lag compensation;

[0013] S3. Establish the updated iterative equations of the two force correction model parameters and calculate the damping C of the test substructure based on the test data. E and stiffness K E :

[0014] Among them, the update iterative equation for establishing the force correction model parameters can be:

[0015]

[0016] In the above formula, the superscript j represents the iteration round, the value of j is not less than 2, λ represents the weight coefficient, and the range of λ is [0,1]; n represents the total number of integration steps; subscript E represents the experimental substructure; subscript m represents the measured value; v and d represent the time-history velocity matrix and time-history displacement matrix of the numerical substructure respectively; i represents the integration time step; F represents the time-history reaction force;

[0017] The update iterative equation for establishing the force correction model parameters can also be:

[0018]

[0019] In the above formula, the value of j is 2;

[0020]

[0021] In the above formula, the value of j is not less than 3, and N represents the total number of iterations;

[0022] S4. Input the test data collected in the previous round of tests into the numerical substructure, solve the motion equation to obtain a new loading command, perform time delay compensation on the loading command and obtain new test data;

[0023] Among them, the last round of correction force input and solution of the motion equation is:

[0024]

[0025] In the above formula, represents the correction force of the test substructure. The specific correction formula can be expressed as follows:

[0026]

[0027] S5. Determine the weight coefficient λ in formula (7) based on the test data of two adjacent rounds and the convergence index;

[0028] S6. Loop S3, S4, and S5 to determine the number of iterations based on the convergence index and the engineering accuracy threshold.

[0029] Preferably, the process of confirming the convergence index includes:

[0030]

[0031] In the above formula, q represents the qth experimental substructure.

[0032] Preferably, before the force correction model parameters are updated in real time according to the previous round of test data, the method further includes comparing the damping C of the test substructures of two adjacent rounds through the optimization module. E and stiffness K EThe iterative convergence of the damping C with high iterative convergence efficiency is selected E and stiffness K E Correct the model parameters for the current force.

[0033] Preferably, after updating the force correction model parameters in real time according to the previous round of test data, the method also includes correcting the measured data of the previous round of test substructure according to the difference between the measured data of the previous round of test substructure and the instruction data of the current round of numerical substructure.

[0034] Preferably, the weight coefficient λ value of the first iteration, that is, the second round, is 0.5; the weight coefficient λ value of other rounds is determined by the calculated value of the convergence index.

[0035] Preferably, a force correction update iterative hybrid test system based on multi-task loading is further provided, which is applied to the above-mentioned force correction update iterative hybrid test method, comprising:

[0036] Numerical simulation module, used to establish numerical models of numerical substructures of prototype structures and numerical models of test substructures;

[0037] The test loading module includes an actuator, a controller, and a time delay compensation unit, which is used to execute the loading command and collect test data;

[0038] Parameter update module, used to calculate force correction model parameters and weight coefficients in real time based on test data;

[0039] The convergence judgment module is used to determine the number of iterations based on the convergence index and the engineering accuracy threshold.

[0040] Preferably, a storage medium is further provided, wherein at least one instruction is stored in the storage medium, and the at least one instruction is loaded and executed by a processor to implement the above-mentioned force correction update iterative hybrid test method.

[0041] Preferably, a force correction update iterative hybrid test device based on multi-task loading is also provided, and the force correction update iterative hybrid test device based on multi-task loading includes a processor, a memory and a sensor array, the memory stores at least one instruction as mentioned above, the sensor array test data, and the processor loads and executes instructions to implement the force correction update iterative hybrid test method based on multi-task loading as mentioned above.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The force correction update iterative hybrid test method based on multi-task loading proposed in this invention develops a force correction model update technology, uses finite element software for refined modeling, uses a servo loading system to load the numerical substructure and the test substructure in sequence, collects test data and inputs it into the numerical substructure, solves the motion equation to obtain a new loading command, performs time lag compensation and obtains new test data, updates the motion equation through the correction force, effectively solves the problem of inconsistent reaction force when numerically solving the motion equation of the numerical substructure, and accelerates the efficiency of iterative convergence. The specific description is as follows,

[0044] If formula (7) is simplified, when the calculation accuracy of the equation is high, then the Kelvin viscoelastic model can characterize the output characteristics of the numerical substructure and the experimental substructure to a certain extent. Then formula (7) can be changed to,

[0045]

[0046] 2. The force correction update iterative hybrid test method based on multi-task loading proposed in this invention adopts the update iterative equation to calculate the parameters of the force correction model parameters, updates the force correction model in real time, and dynamically adjusts the adaptive weight coefficient λ, thereby improving the accuracy of the force correction model and achieving boundary coordination of the substructure.

[0047] If the boundaries between substructures are coordinated, then formula (10) can be transformed into Substituting formula (10) into formula (6), formula (6) can be changed to,

[0048]

[0049] 3. The force correction update iterative hybrid test method based on multi-task loading proposed in the present invention develops an update iterative technology for the force correction model, which avoids the problem of calculation time lag. The numerical substructure can be modeled in a refined manner, thereby improving the accuracy of the numerical substructure and reducing the error caused by model simplification.

[0050] 4. The force correction update iterative hybrid test method based on multi-task loading proposed in the present invention realizes the goal that multiple rounds of loading of a single test substructure can test the dynamic performance of multiple test substructures, effectively reduces the requirements for real-time hybrid test method operation technology and laboratory test conditions, reduces dependence on real-time synchronous loading equipment, reduces operation complexity, and saves test costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Updated iterative hybrid test method flow chart for force correction based on multi-task loading;

[0052] Figure 2This is a flow chart of the principle of the force correction update iterative hybrid test method based on multi-task loading (taking a seven-story frame vibration / seismic structure equipped with six isolation supports as an example);

[0053] Figure 3 This is a flow chart of the principle of the force correction update iterative hybrid test method based on multi-task loading (taking a four-span bridge vibration / seismic structure equipped with three viscous dampers as an example);

[0054] Figure 4 This is a flow chart of the principle of the force correction update iterative hybrid test method based on multi-task loading (taking a seven-story frame vibration / seismic structure equipped with seven viscous dampers as an example);

[0055] Figure 5 Flowchart of the iterative hybrid testing system for force correction update based on multi-task loading. DETAILED DESCRIPTION

[0056] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0057] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show structures and / or processing steps closely related to the solutions according to the present invention, while other details that are not closely related to the present invention are omitted. Specific implementation method one:

[0059] This embodiment only provides a preferred implementation method, which is a force correction update iterative hybrid test method based on multi-task loading. By establishing a numerical model of the numerical substructure of the prototype structure and a numerical model of the test substructure, the first round of motion equations are solved to obtain loading commands, the loading commands are preprocessed and test data are obtained. The experimental data can be but not limited to displacement, force, acceleration, etc., and an update iterative equation for the force correction model parameters is established. The force correction model parameters are updated in real time according to the previous round of test data, the previous round of correction force is input, the updated motion equations are solved, iterative loading is performed and test data is collected to determine whether the convergence index reaches the engineering accuracy threshold. If so, the iteration is terminated; if not, the process of updating the model parameters and loading commands is cyclically updated until the convergence index reaches the engineering accuracy threshold. Specific implementation method two:

[0061] This embodiment only provides a preferred implementation, in which the force correction model parameters can include but are not limited to the damping C of the test substructure. E , stiffness K Eand the weight coefficient λ value to solve the inconsistency problem between the numerical substructure and the experimental substructure reaction force and speed up the iterative convergence. Specific implementation method three:

[0063] This embodiment only provides a preferred implementation method. Specifically, Figure 2 As shown, taking a high-rise vibration reduction / seismic structure equipped with multiple isolation supports as an example, the basic principle and usage steps of the method of the present invention are explained. In this embodiment, when the prototype structure is a high-rise vibration reduction structure, the high-rise structure is taken as a numerical substructure, and finite element software is used for refined modeling. One of the isolation supports is taken as a test substructure, and a servo loading system is used to load it in sequence to carry out a force correction update iterative hybrid test based on multi-task loading. The specific process of the force correction update iterative hybrid test method includes:

[0064] S1. Establish a finite element model of a seven-story frame structure as the numerical model of the prototype structure's numerical substructure and the numerical model of the test substructure. Assuming that the restoring forces of the isolation bearings are all zero, use the central difference method to solve the numerical simulation system to obtain the loading commands for the first round of experiments.

[0065] The motion equation can be expressed as:

[0066]

[0067] In the above formula, M, C, and K represent the mass matrix, damping matrix, and stiffness matrix of the numerical substructure, respectively; Respectively represent the time-history acceleration matrix, time-history velocity matrix, and time-history displacement matrix of the numerical substructure in the first round, step i; represents the time-history reaction of the numerical model of the test substructure in the first round; the subscript N represents the numerical substructure; i represents the integration time step; a g,i represents the earthquake acceleration excitation;

[0068] S2. Perform time-delay compensation on the loading command, send the compensated command to the controller, and have the actuator execute the command on a single seismic isolation bearing. Finally, collect test data, that is, obtain test data based on the loading command after time-delay compensation; wherein, the time-delay compensation method refers to correcting the time delay between numerical calculation and physical loading through an algorithm or control strategy to ensure real-time synchronization between the loading command and the structural response. The time-delay compensation method adopts an existing compensation method, which can be but not limited to polynomial extrapolation or a simpler first-order lag compensation, such as the forward Euler method. The hybrid test needs to complete the "calculation-loading-feedback" closed loop within each integral step. The use of time-delay compensation can avoid data loss of synchronization due to delays.

[0069] S3. Establish the updated iterative equations of the two force correction model parameters and calculate the damping C of the test substructure based on the test data.E and stiffness K E , while updating the parameters of the force correction model in real time, the present invention provides two iterative equations for updating the parameters of the force correction model, wherein the first one is performed in a secant manner, and the second one is performed in a tangent manner;

[0070] Among them, the update iterative equation for establishing the force correction model parameters can be:

[0071]

[0072] In the above formula, the superscript j represents the iteration round, and the value of j is not less than 2. λ represents the weight coefficient, and the range of λ is [0,1]. n represents the total number of integration steps. The subscript E represents the experimental substructure. The subscript m represents the measured value. v and d represent the time-history velocity matrix and the time-history displacement matrix of the numerical substructure, respectively. i represents the integration time step. F represents the time-history reaction force.

[0073] The update iterative equation for establishing the force correction model parameters can also be:

[0074]

[0075] In the above formula, the value of j is 2;

[0076]

[0077] In the above formula, the value of j is not less than 3, and N represents the total number of iterations.

[0078] Specifically, formulas (13), (15) and (16) can be set with a restriction during implementation. Preferably, if in the sth iteration (s≥3), or Then the measured data in the sth round will not be considered. For example, the model parameters in the sth round of iteration are updated to and

[0079] S4. Input the test data collected in the previous round of tests into the numerical subframe structure, i.e., the test data of the j-1th round. The data is the collected restoring force. The motion equation is solved by the central difference method to obtain the displacement loading command of the seismic isolation bearing. The loading command is compensated using the time lag compensation method. Then, the compensated command is sent to the controller. The actuator executes the command on a single seismic isolation bearing. Finally, the test data such as displacement and force are collected. Among them, the correction force input and the motion equation solved in the previous round are:

[0080]

[0081] In the above formula, represents the correction force of the test substructure. The specific correction formula can be expressed as follows:

[0082]

[0083] Specifically, in the force-corrected updated iterative hybrid test method based on multi-task loading, the above-mentioned S2 and S4 are performed by loading a small number of test substructures with a limited number of test loading devices, and the seismic responses of multiple test substructures in the prototype structure are reproduced through the multi-task loading technology. For example, time-history loading commands for the 1st layer, the 2nd layer, ..., the nth layer are sent to the controller one by one, and then a set of actuators loads the single test substructure, and finally the time-history measured forces and displacements of the 1st layer, the 2nd layer, ..., the nth layer are collected respectively.

[0084] S5. Determine the weight coefficient λ in formula (7) based on the test data of two adjacent rounds and the convergence index;

[0085] S6. Loop S3, S4, and S5 to determine the number of iterations based on the convergence index and the engineering accuracy threshold. Specific implementation method four:

[0087] This embodiment only provides a preferred implementation method. Specifically, the process of confirming the convergence index includes:

[0088]

[0089] In the above formula, q represents the qth experimental substructure. Specific implementation method five:

[0091] This embodiment only provides a preferred implementation method. Specifically, before updating the force correction model parameters in real time based on the previous round of test data, it also includes comparing the damping C of the test substructures in two adjacent rounds through the optimization module. E and stiffness K E The iterative convergence of the damping C with high iterative convergence efficiency is selected E and stiffness K E To correct the model parameters for the current force, specifically, an optimization module is embedded in the numerical system, using The iterative convergence of the calculation is Compare the iterative convergence of the former and discard it if the former has faster convergence efficiency. Benefit from the advantages of offline iterative hybrid experiments. Specific implementation method six:

[0093] This embodiment only provides a preferred implementation method. After updating the force correction model parameters in real time according to the previous round of test data, it also includes correcting the measured data of the previous round of test substructure according to the difference between the measured data of the previous round of test substructure and the instruction data of the current round of numerical substructure. Specifically, the measured force of the j-1 round of test substructure is corrected by using the difference between the measured data such as displacement and speed of the j-1 round of test substructure and the instruction data such as displacement and speed of the j round of numerical substructure. Specific implementation method seven:

[0095] This embodiment only provides a preferred implementation method: specifically, when force correction is carried out for the first time, that is, the second round of testing, the weight coefficient λ can be but is not limited to 0.5. In other test rounds, that is, the jth round of testing, the λ value with the fastest convergence efficiency is determined by calculating the value of the convergence index.

[0096] Preferably, the solution of the λ parameter can be obtained by numerically simulating the displacement d N Compared with the experimentally measured displacement d Em Parameter optimization is achieved through convergence analysis. Furthermore, in equations (19-1) and (20-1), the parameter λ ranges from [0,1], and its specific value can be dynamically determined according to the convergence characteristics of each round of iteration. The introduction of this parameter is intended to evaluate the degree of dependence of the force correction proxy model on the damping or stiffness characteristics of the test substructure. During the calculation process, λ usually adopts an optimization strategy starting from 0 and gradually increasing to 1 in steps of 0.1 to obtain the best parameter value. Due to the independence of the calculation of the offline RTHT numerical system, the calculation process of this module hardly generates additional resource consumption. When equipped with a high-performance computer, this part of the calculation can be completed in a very short time, and the λ value for coordinated adaptation between substructures can be quickly determined, thereby improving the overall matching efficiency of the system. The optimal λ value can be directly obtained through numerical calculation, reducing the cost of experimental trial and error. In addition, this design allows the weight coefficient λ to be subjected to convergence analysis from the second round of iteration.

[0097]

[0098] Specific implementation method eight:

[0100] This embodiment only provides a preferred implementation method. The present invention is applicable to other large and complex vibration reduction structures with similar basic principles. Specifically, Figure 3As shown, the basic principles and application steps of the method of the present invention are explained using a bridge vibration reduction / seismic structure as an example. This embodiment provides a method for a four-span bridge vibration reduction / seismic structure prototype structure. The bridge structure is used as a numerical substructure and refined modeling is performed using finite element software. One of the viscous dampers is used as a test substructure and sequentially loaded using a servo loading system. A hybrid test based on multi-task loading, force correction, update and iteration is carried out. The specific test process is as follows:

[0101] Step 1: Establish a finite element model of the bridge structure. Assuming that the restoring force of the viscous damper is zero, use the central difference method to solve the numerical simulation system to obtain the loading command for the first round of experiments. The motion equation of step 1 can be expressed as:

[0102]

[0103] In the above formula, M, C, and K are the mass matrix, damping matrix, and stiffness matrix of the bridge structure respectively; are the time-history acceleration matrix, time-history velocity matrix, and time-history displacement matrix of the bridge structure in the first round, step i; the subscript N represents the bridge structure; i is the integration time step; a g,i is the earthquake acceleration excitation.

[0104] Step 2: Compensate the displacement loading command for time lag, send the compensated command to the controller, and have the actuator execute the command on a single viscous damper. Finally, collect test data such as displacement and force.

[0105] Step 3: Calculate the damping C of the viscous damper using formula (22) or formula (23) to formula (25) E and stiffness K E , and update the parameters of the force correction model in real time; the formula of step three is as follows,

[0106] The first method of updating model parameters is

[0107] In iteration round j (j≥2),

[0108]

[0109] In the above formula, λ is the weight coefficient, and the range of λ is [0,1]; n is the total number of integration steps; the subscript E represents the viscous damper; the subscript m represents the measured value; and the superscript j represents the iteration round.

[0110] The second way to update model parameters is:

[0111] When in the second round of iteration,

[0112]

[0113] In iteration j (j≥3),

[0114]

[0115] In the above formula, N is the total number of iterations.

[0116] Specifically, formulas (22), (24) and (25) will also set a restriction when they are implemented. If in the sth round of iteration, where s is not less than 3, or Then the measured data in the sth round will not be considered. For example, the model parameters in the sth round of iteration are updated to and

[0117] Step 4: First, input the restoring force collected in the previous round of tests, i.e., the j-1th round, into the bridge structure. The motion equation is solved by the central difference method, i.e., formula (26), to obtain the displacement loading command of the viscous damper. The time-delay compensation method is used to compensate the loading command. Then, the compensated command is sent to the controller, and the actuator executes the command on a single viscous damper. Finally, the displacement and force test data are collected.

[0118]

[0119] In the above formula, is the correction force of the viscous damper (3), and the specific correction formula can be expressed as follows:

[0120]

[0121] Step 5: Determine the adaptive weight coefficient λ in formula (27) based on the test data and convergence index of two adjacent rounds; specifically, λ in the second round can be set to 0.5.

[0122] Step 6: Repeat steps 3, 4, and 5, and determine the number of iterations based on the convergence index and engineering accuracy requirements. The convergence index can be expressed as follows:

[0123]

[0124] In the above formula, q is used to refer to the qth viscous damper, where the value of q is between 1 and 3. Specific implementation method nine:

[0126] This embodiment only provides a preferred implementation method. The present invention is applicable to other large and complex vibration reduction structures with similar basic principles. Specifically, Figure 4As shown, the basic principles and application steps of the present method are illustrated using a frame-based vibration / shock structure equipped with seven viscous dampers as an example. In this embodiment, when the prototype structure is a frame-based vibration / shock structure equipped with seven viscous dampers, the frame structure is used as the numerical substructure and refined modeling is performed using finite element software. One of the viscous dampers is used as the test substructure, and a servo loading system is used to sequentially load the dampers, conducting a hybrid test based on multi-task loading, force correction, and iterative updates. The specific test process is as follows:

[0127] Step 1: Establish a finite element model of the frame structure. Assuming that the restoring force of the viscous damper is zero, use the central difference method to solve the numerical simulation system to obtain the loading command for the first round of experiments. The motion equation of step 1 can be expressed as:

[0128]

[0129] In the above formula, M, C, and K are the mass matrix, damping matrix, and stiffness matrix of the frame structure respectively; are the time-history acceleration matrix, time-history velocity matrix, and time-history displacement matrix of the frame structure in the first round, step i; the subscript N represents the frame structure; i is the integration time step; a g,i is the earthquake acceleration excitation.

[0130] Step 2: Compensate the displacement loading command for time lag, send the compensated command to the controller, and have the actuator execute the command on a single viscous damper. Finally, collect test data such as displacement and force.

[0131] Step 3: Calculate the damping C of the viscous damper using formula (32) or formula (33) to formula (35) E and stiffness K E , and update the parameters of the force correction model in real time; the formula of step three is as follows,

[0132] The first method of updating model parameters is

[0133] In iteration round j (j≥2),

[0134]

[0135] In the above formula, λ is the weight coefficient, and the range of λ is [0,1]; n is the total number of integration steps; the subscript E represents the viscous damper; the subscript m represents the measured value; and the superscript j represents the iteration round.

[0136] The second way to update model parameters is:

[0137] When in the second round of iteration,

[0138]

[0139] In iteration j (j≥3),

[0140]

[0141] In the above formula, N is the total number of iterations.

[0142] Specifically, formulas (32), (34) and (35) will also set a limit when they are implemented. If in the sth round of iteration, where the value of s is not less than 3, or Then the measured data in the sth round will not be considered. For example, the model parameters in the sth round of iteration are updated to and

[0143] Step 4: First, input the restoring force collected in the previous round, i.e., the j-1th round of test, into the frame structure. The motion equation is solved by the central difference method, i.e., formula (36), to obtain the displacement loading command of the viscous damper. The loading command is compensated using the time-delay compensation method. Then, the compensated command is sent to the controller. The actuator executes the command on a single viscous damper, and finally, the displacement, force and other test data are collected.

[0144]

[0145] Where, is the correction force of the viscous damper (3), and the specific correction formula can be expressed as follows:

[0146]

[0147] Step 5: Determine the adaptive weight coefficient λ in formula (37) based on the test data and convergence index of two adjacent rounds; specifically, λ in the second round can be set to 0.5.

[0148] Step 6: Repeat steps 3, 4, and 5 in this embodiment, and determine the number of iterations based on the convergence index and engineering accuracy requirements. The convergence index can be expressed as follows:

[0149]

[0150] In the above formula, q is used to refer to the qth viscous damper, where the value of q ranges from 1 to 7. Specific implementation method ten:

[0152] This embodiment only provides a preferred implementation method. The present invention provides a force correction update iterative hybrid test system based on multi-task loading, such as Figure 5 As shown in FIG, the iterative hybrid test method applied to force correction update includes:

[0153] Numerical simulation module, used to establish numerical models of numerical substructures of prototype structures and numerical models of test substructures;

[0154] The test loading module includes an actuator, a controller, and a time delay compensation unit, which is used to execute the loading command and collect test data;

[0155] Parameter update module, used to calculate force correction model parameters and weight coefficients in real time based on test data;

[0156] The convergence judgment module is used to determine the number of iterations based on the convergence index and the engineering accuracy threshold. Specific implementation method eleven:

[0158] This embodiment only provides a preferred implementation method, which is a storage medium. The storage medium stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the above-mentioned time-varying parameter identification method; the storage medium described in this embodiment includes but is not limited to a hard disk, a USB flash drive, an embedded system storage instruction set, etc., and supports real-time data processing and parameter updating. Specific implementation method 12:

[0160] This embodiment only provides a preferred implementation method. This implementation method is a force correction update iterative hybrid test device based on multi-task loading. The force correction update iterative hybrid test device based on multi-task loading includes a processor, a memory and a sensor array. The memory stores at least one of the above instructions. The sensor array collects response data in real time. The processor loads and executes instructions to implement the above-mentioned force correction update iterative hybrid test method based on multi-task loading and outputs a warning signal. The force correction update iterative hybrid test device can be but is not limited to integrating a multi-channel data acquisition module, an edge computing unit and a 4G communication module to realize "end-cloud" collaborative warning. The devices mentioned in this implementation method include but are not limited to mobile devices, workstations, etc.

[0161] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A force correction update iterative hybrid test method based on multi-task loading, characterized by: The force correction update iterative hybrid test method comprises establishing a numerical model of a numerical substructure of a prototype structure and a numerical model of a test substructure, solving a first round of motion equations to obtain a loading command, preprocessing the loading command and obtaining test data, establishing an update iterative equation for force correction model parameters, updating the force correction model parameters in real time according to the last round of test data, inputting the last round of correction force, solving the updated motion equation, executing iterative loading and collecting test data, determining whether a convergence index reaches an engineering accuracy threshold, and terminating the iteration if so; If not, the process of updating model parameters and loading commands is cyclically repeated until the convergence index reaches the engineering accuracy threshold.

2. A force correction update iterative hybrid test method based on multi-task loading according to claim 1, characterized in that: The force correction model parameters include the damping C of the test substructure E , stiffness K E and the weight coefficient λ value.

3. A force correction update iterative hybrid test method based on multi-task loading according to claim 2, characterized in that: The force correction update iterative hybrid test method includes: S1. Establish numerical models of the numerical substructure of the prototype structure and the numerical model of the test substructure, solve the first round of motion equations to obtain loading commands, including obtaining loading commands for the first round of tests: The motion equation can be expressed as: In the above formula, M, C, and K represent the mass matrix, damping matrix, and stiffness matrix of the numerical substructure, respectively; Respectively represent the time-history acceleration matrix, time-history velocity matrix, and time-history displacement matrix of the numerical substructure in the first round, step i; represents the time-history reaction of the numerical model of the test substructure in the first round; the subscript N represents the numerical substructure; i represents the integration time step; a g,i represents the earthquake acceleration excitation; S2. performing time lag compensation on the loading command, and acquiring test data according to the loading command after time lag compensation; S3. Establish the updated iterative equations of the two force correction model parameters and calculate the damping C of the test substructure based on the test data. E and stiffness K E : Among them, the update iterative equation for establishing the force correction model parameters can be: In the above formula, the superscript j represents the iteration round, the value of j is not less than 2, λ represents the weight coefficient, and the range of λ is [0,1]; n represents the total number of integration steps; subscript E represents the experimental substructure; subscript m represents the measured value; v and d represent the time-history velocity matrix and time-history displacement matrix of the numerical substructure respectively; i represents the integration time step; F represents the time-history reaction force; The update iterative equation for establishing the force correction model parameters can also be: In the above formula, the value of j is 2; In the above formula, the value of j is not less than 3, and N represents the total number of iterations; S4. Input the test data collected in the previous round of tests into the numerical substructure, solve the motion equation to obtain a new loading command, perform time delay compensation on the loading command and obtain new test data; Among them, the last round of correction force input and solution of the motion equation is: In the above formula, represents the correction force of the test substructure. The specific correction formula can be expressed as follows: S5. Determine the weight coefficient λ in formula (7) based on the test data of two adjacent rounds and the convergence index; S6. Loop S3, S4, and S5 to determine the number of iterations based on the convergence index and the engineering accuracy threshold.

4. The force correction update iterative hybrid test method based on multi-task loading according to claim 3 is characterized by: The process of confirming the convergence index includes: In the above formula, q represents the qth experimental substructure.

5. The force correction update iterative hybrid test method based on multi-task loading according to claim 4 is characterized in that: The method of updating the force correction model parameters in real time based on the test data of the previous round also includes comparing the damping C of the test substructures of two adjacent rounds through the optimization module. E and stiffness K E The iterative convergence of the damping C with high iterative convergence efficiency is selected E and stiffness K E Correct the model parameters for the current force.

6. The hybrid test method of force correction update iteration based on multi-task loading according to claim 5, characterized in that: After updating the force correction model parameters in real time according to the previous round of test data, the method also includes correcting the measured data of the previous round of test substructure according to the difference between the measured data of the previous round of test substructure and the instruction data of the current round of numerical substructure.

7. A force correction update iterative hybrid test method based on multi-task loading according to any one of claims 1 to 6, characterized in that: In the first iteration, i.e. the second round, the revised weight coefficient λ value is 0.5; in other rounds, the weight coefficient λ value is determined by the calculated value of the convergence index.

8. A force correction update iterative hybrid test system based on multi-task loading, applied to the force correction update iterative hybrid test method according to any one of claims 1 to 7, characterized in that: include: Numerical simulation module, used to establish numerical models of numerical substructures of prototype structures and numerical models of test substructures; The test loading module includes an actuator, a controller, and a time delay compensation unit, which is used to execute the loading command and collect test data; Parameter update module, used to calculate force correction model parameters and weight coefficients in real time based on test data; The convergence judgment module is used to determine the number of iterations based on the convergence index and the engineering accuracy threshold.

9. A storage medium, characterized in that: The storage medium stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the force correction update iterative hybrid test method according to any one of claims 1 to 7.

10. A force correction update iterative hybrid test device based on multi-task loading, characterized in that: The force correction update iterative hybrid test equipment based on multi-task loading includes a processor, a memory and a sensor array, the memory stores at least one instruction as described in claim 9, the sensor array test data, and the processor loads and executes instructions to implement the force correction update iterative hybrid test method based on multi-task loading as described in any one of claims 1 to 7.

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