Multi-loading rate hybrid test method for multi-type test substructures

Abstract

The present invention discloses a multi-loading rate hybrid test method for multi-type test substructures, which divides the research object into two substructures: the first division is based on the researcher's concern for the structural part, and the part of greatest concern is taken out as the test substructure, and the rest of the structure is the numerical substructure; the second division is based on the degree of dependence of the components in the test substructure on the rate, and the part that depends on the rate is taken out as the rate-type test substructure, and the rest is the conventional test substructure. The first division takes out the most concerned structural part as the test substructure, and conducts physical loading tests, saving the cost of making the structural model; the second division divides the test substructure into rate-type and conventional test substructures based on the rate dependence of the test substructure, realizing the fast and slow separation of the physical test, that is, reducing the frequency requirement of the conventional test substructure test on the actuator, and also reducing the output tonnage requirement of the rate-type test substructure test on the actuator.

Description

Technical Field

[0001] The present invention belongs to the field of seismic testing of civil engineering, and in particular relates to a multi-loading rate mixed testing method for multi-type test substructures. Background Art

[0002] With the advancement of earthquake engineering and socioeconomic development, the seismic fortification requirements for building structures have shifted from ensuring basic life safety to ensuring both life and property safety, and towards a resilience-based seismic design philosophy. This resilience-based seismic design philosophy represents a new approach to disaster prevention, mitigation, and sustainable development. To improve structural seismic resilience, new rate-dependent damper technologies have been developed and applied. Physical testing is essential for evaluating the dynamic performance of these new structural systems.

[0003] The hybrid testing method separates the difficult-to-model or interesting parts of a structure into a test substructure, while the remaining structure serves as a numerical substructure. These two components are combined via a coordinator to test the structural dynamic response. Physical loading of the test substructure yields realistic results, while computer simulation of the numerical substructure significantly reduces testing costs and saves research funds.

[0004] Hybrid testing is currently divided into slow hybrid testing and real-time hybrid testing. For slow hybrid testing, the test substructure must be displacement-dependent, such as beams, columns, and beam-column joints in frame structures. Low-frequency actuators with high output are typically used to control the substructure boundaries. For real-time hybrid testing, the test substructure must be rate-dependent, such as viscous dampers, tuned mass dampers, and tuned liquid dampers. Low-output medium- and high-frequency actuators or vibration tables are typically used to control the substructure boundaries.

[0005] When using a hybrid testing method to evaluate the dynamic performance of a ductile structure equipped with a novel rate-type damper, it is necessary to remove the portion of the structure containing the rate-type damper as a test substructure. Due to the presence of the damper, the test substructure requires real-time hybrid testing to investigate the damper's operating state under dynamic loads and the crack development, damage location, and failure mode of the structure after the rate-type damper is installed.

[0006] The above approach places too high demands on the test hardware. For example, the actuator not only has a large output tonnage but also a high frequency, which is difficult for structural laboratories to meet. Even if it is met, real-time loading is difficult and real-time testing is difficult to conduct. It is not suitable as a method for evaluating and promoting the performance of new resilient structures. Summary of the Invention

[0007] The purpose of the present invention is to provide a multi-loading rate hybrid test method for multiple types of test substructures, so as to solve the problem that existing test methods are difficult to conduct tests on large structures containing rate-dependent components.

[0008] In order to achieve the above object, the technical solution of the present invention is:

[0009] A multi-loading rate hybrid test method for multiple types of test substructures divides the research object into two substructures:

[0010] The first sub-structure division is based on the degree of concern for the research object. The most concerned structural part is taken out as the experimental sub-structure and subjected to physical loading test in the laboratory. The remaining structural parts are taken as numerical sub-structures and simulated in the computer.

[0011] The second substructure division is based on the degree of dependence of the components in the test substructure on the rate. The rate-dependent structural part is taken out as the rate-type test substructure, and the remaining structural parts are conventional test substructures.

[0012] Furthermore, after two substructure divisions, there are three substructures in total: a numerical substructure, a conventional test substructure, and a rate test substructure; these three substructures collaboratively complete the dynamic performance evaluation of resilient structures containing rate-dependent components through time domain boundary coordination technology.

[0013] Furthermore, the numerical substructure is simulated in a computer, and there is no requirement for the speed of calculation; the conventional test substructure can be damaged and destroyed during the test, and its test type is a slow loading test; the rate test substructure is repeatable, that is, after multiple physical loadings, its physical properties are almost restored to their original state after a period of static state, and its test type is a real-time loading test.

[0014] Furthermore, the time domain boundary coordination technology is as follows: the numerical substructure quickly calculates to implement the current command, maintains the current state after completion, and waits for the conventional test substructure and rate test substructure to be loaded; the rate test substructure is loaded in real time to implement the current command, and returns to the original state after completion, waiting for the conventional test substructure to be loaded; the conventional test substructure finally completes the loading task and maintains the current state; at this time, the three types of substructures wait for the command of the next integration step.

[0015] Furthermore, the state includes the displacement, velocity and acceleration of the substructure, and the command includes the displacement command, velocity command, acceleration command and force command.

[0016] Furthermore, the specific test steps are as follows:

[0017] (1) The dynamic equations of the numerical substructure, conventional test substructure, and rate-dependent test substructure under earthquake action are established as follows:

[0018] Where M and C are the mass matrix and damping matrix of the overall structure, respectively, and R is the restoring force vector of the structure. and x are the acceleration, velocity and displacement vectors of the structure, respectively. The subscripts N, RE and CE refer to the numerical substructure, rate test substructure and conventional test substructure, respectively. i,g is the seismic wave acceleration record, ι is the impact vector, and i is the integration step;

[0019] (2) Solve the dynamic equations using the step-by-step integration algorithm to obtain the three substructure motion commands at the i-th integration step, namely, the displacement x of the numerical substructure i,N , displacement x of the conventional test substructure i,CE The displacement and velocity of the substructure in the rate-type test (x i,RE , );

[0020] (3) The numerical substructure is simulated in the computer to calculate the command x of the i-th integration step i,N , and obtain the numerical substructure partial restoring force R i,N , waiting for the loading of the conventional test substructure and the rate test substructure;

[0021] (4) The rate-type test substructure conducts real-time tests in the laboratory and loads the command (x i,RE , ), and obtain the rate-type test substructure restoring force R of the current step i,RE , then restore to the initial state of the rate-type test substructure, that is, the displacement and velocity are 0, and wait for the conventional test substructure to be loaded;

[0022] (5) The conventional test substructure is tested slowly in the laboratory, and the command x of the i-th integration step is loaded slowly. i,CE , get the conventional test substructure restoring force R of the current step i,CE ;

[0023] (6) Substitute the restoring forces of the three substructures into the dynamic equations of step (1);

[0024] (7) Repeat steps (2) to (6) until the test is completed.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] The present invention proposes a multi-loading rate hybrid test method for multiple types of test substructures. The method undergoes two substructure divisions instead of one. The first division takes out the structural part that researchers are most concerned about as the test substructure to carry out physical loading tests, which greatly saves the cost of making structural models. The second division divides the test substructure into rate-type test substructures and conventional test substructures based on rate dependence, thereby realizing the fast and slow separation of tests, reducing the frequency requirements of the actuator for the conventional test substructure test, and reducing the output tonnage requirements of the actuator for the rate-type test substructure test, ensuring that laboratories and test personnel can complete such tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of the multi-loading rate hybrid test method for multiple types of test substructures;

[0028] Figure 2 Schematic diagram of a three-layer frame structure equipped with a viscous damper;

[0029] Figure 3 Schematic diagram of the physical loading test in the laboratory for the bottom layer as a test substructure;

[0030] Figure 4 Schematic diagram of the remaining two layers as numerical substructures simulated in computer;

[0031] Figure 5 This is a schematic diagram of a substructure after secondary division in Example 1;

[0032] Figure 6 A three-story frame structure with water tanks on the top floor;

[0033] Figure 7 Schematic diagram of the physical loading test in the laboratory for the third-layer frame containing the water tank as a test substructure;

[0034] Figure 8 Schematic diagram of the lower two layers simulated in computer as numerical substructures;

[0035] Figure 9 This is a schematic diagram of the secondary division substructure of Example 2.

[0036] In the figure: 1-viscous damper, 2-actuator, 3-water tank. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0038] In order to solve the problem that existing test methods are difficult to conduct tests on large structures containing rate-dependent components, the present invention proposes a multi-loading rate hybrid test method for multiple types of test substructures, involving structures with repeatable components and parts that can be damaged or destroyed.

[0039] The multi-loading rate mixed test method for multi-type test substructures of the present invention divides the research object into two parts. Figure 1 As shown, the first sub-structure division is based on the researchers' concern for the research object. The structural part that the researchers are most concerned about is taken out as the test sub-structure, and a physical loading test is carried out in the laboratory. The remaining structural parts are used as numerical sub-structures and simulated in the computer. The sub-structure is divided twice based on the rate dependence of the components in the test sub-structure. The rate-dependent components are taken out as rate-type test sub-structures, and the remaining parts are conventional test sub-structures. The method of the present invention divides the research object into sub-structures twice. The first division takes out the structural part that the researchers are most concerned about as the test sub-structure and carries out a physical loading test, which greatly saves the cost of making the structural model. The second division divides the test sub-structure into rate-type test sub-structures and conventional test sub-structures based on rate dependence, thereby realizing the separation of fast and slow tests, reducing the frequency requirements of the conventional test sub-structure test on the actuator, and reducing the output tonnage requirements of the rate-type test sub-structure test on the actuator.

[0040] Furthermore, the numerical substructure is simulated on a computer, meeting both slow and real-time calculation requirements. The conventional test substructure is a slow loading test, while the rate test substructure is a real-time loading test. Conventional test substructures can be damaged and destroyed, and are not repeatable, so they are slow loading tests. Rate test substructures are repeatable, and after multiple physical loadings and a period of rest, their physical properties return to near-original state. These tests are real-time loading tests.

[0041] Furthermore, after two substructure divisions, there are three substructures in total: numerical substructure, conventional test substructure, and rate test substructure. These three substructures work together to complete the dynamic performance evaluation of resilient structures containing rate-related components through time domain boundary coordination technology.

[0042] The time domain boundary coordination technology is as follows: the numerical substructure quickly calculates to implement the current command, maintains the current state after completion, and waits for the conventional test substructure to be loaded; the rate test substructure is loaded in real time to implement the current command, and returns to the original state after completion, and waits for the conventional test substructure to be loaded; the conventional test substructure finally completes the loading task to implement the current command and maintains the current state; at this time, the three substructures wait for the next command.

[0043] The state refers to the displacement, velocity, and acceleration of the substructure; the command can be a displacement, velocity, acceleration, force, and other commands.

[0044] Example 1:

[0045] Taking a viscous damper-frame structure as an example, the basic principles and steps of the method of the present invention are explained. Viscous dampers have advantages such as a full hysteresis curve, strong energy dissipation capacity, no additional stiffness added to the frame, and no further enhancement of seismic effects. They also have simple construction, reasonable cost, and repeatable operation. They are widely used in civil engineering, machinery, bridges, aerospace, and other fields. Physical testing of the viscous damper-frame system is required to select the viscous damper, verify its shock absorption effect, and determine the damage and failure modes of the frame structure.

[0046] Figure 2 The figure is a schematic diagram of a three-story frame structure equipped with a viscous damper. Since the bottom layer of the frame structure is relatively weak and is equipped with a viscous damper 1, in order to observe the dynamic performance of the bottom layer under earthquake action, the bottom layer is selected as the test substructure and a physical loading test is carried out in the laboratory using an actuator 2. Figure 3 The remaining two layers are simulated in the computer as numerical substructures, as shown in Figure 4 As shown in . The components in the test substructure are divided into substructures based on the rate correlation. The force of the viscous damper in the bottom frame is related to the rate, while the frame structure is independent of the rate. Therefore, the viscous damper is divided into a rate-type test substructure, and the rest of the frame is a conventional test substructure, as shown in Figure 5 shown.

[0047] Therefore, the three-layer frame structure equipped with viscous dampers is divided into three parts: a numerical substructure, a conventional test substructure, and a rate test substructure. The numerical substructure uses computer simulation, the conventional test substructure is loaded with an actuator with high output tonnage and low frequency, and the rate test substructure is loaded with an actuator with low output tonnage and high frequency. The present invention is used to conduct mixed tests on the three substructures. The specific process is as follows:

[0048] (1) Establish dynamic equations for numerical substructures, conventional test substructures, and rate-dependent test substructures under earthquake action

[0049] Where M and C are the mass matrix and damping matrix of the overall structure, respectively, and R is the restoring force vector of the structure. and x are the acceleration, velocity and displacement vectors of the structure, respectively. The subscripts N, RE and CE refer to the numerical substructure, rate test substructure and conventional test substructure, respectively. i,g is the seismic wave acceleration record, ι is the impact vector, and i is the integration step, i.e., the number of executions, which is determined by the seismic wave length and the integration time interval selected by the user;

[0050] (2) Use the stepwise difference method to solve the dynamic equations and obtain the three substructure motion commands of the i-th integration step, namely the displacement x of the numerical substructure i,N , displacement x of the conventional test substructure i,CE The displacement and velocity of the substructure in the rate-type test (x i,RE , );

[0051] (3) The numerical substructure is simulated in the computer to calculate the command x of the i-th integration step i,N , and obtain the numerical substructure partial restoring force R i,N , waiting for the conventional test substructure to be loaded;

[0052] (4) The rate-type test substructure conducts real-time tests in the laboratory and loads the command (x i,RE , ), and obtain the rate-type test substructure restoring force R of the current step i,RE , then restore to the initial state of the rate-type test substructure, that is, the displacement and velocity are 0, and wait for the conventional test substructure to be loaded;

[0053] (5) The conventional test substructure is tested slowly in the laboratory, and the command x of the i-th integration step is loaded slowly. i,CE , get the conventional test substructure restoring force R of the current step i,CE ;

[0054] (6) Substitute the three substructure restoring forces into the dynamic equation of (1);

[0055] (7) Repeat (2) to (6) until the end of the experiment.

[0056] Example 2:

[0057] Taking the water tank-frame structure as an example, the basic principle and application steps of the method of the present invention are explained. In order to verify the shock absorption effect of the water tank and the damage and failure mode of the frame structure, it is necessary to carry out physical testing on the water tank-frame structure system.

[0058] Figure 6The top floor of the three-story frame structure is equipped with a water tank. Since the top floor of the frame structure has a large vibration amplitude under earthquake action, and the purpose of the top floor water tank 3 is to reduce vibration, in order to observe the dynamic performance of the third floor frame under earthquake action, the third floor frame equipped with the water tank is selected as the test substructure and a physical loading test is carried out in the laboratory. Figure 7 The remaining two layers are simulated in the computer as numerical substructures, as shown in Figure 8 As shown in the figure, the components in the test substructure are divided into substructures based on the rate correlation. The force on the water tank is related to the rate, while the frame structure is independent of the rate. Therefore, the water tank is divided into a rate-type test substructure, and the third-layer frame is a conventional test substructure, as shown in the figure. Figure 9 shown.

[0059] Therefore, the three-layer frame structure equipped with a water tank is divided into three parts: a numerical substructure, a conventional test substructure, and a rate test substructure. The numerical substructure uses computer simulation, the conventional test substructure selects an actuator with high output tonnage and low frequency to load, and the rate test substructure selects an actuator with low output tonnage and high frequency to load. Using this invention, a mixed test is carried out on the three substructures. The specific process is as follows:

[0060] (1) Establish dynamic equations for numerical substructures, conventional test substructures, and rate-dependent test substructures under earthquake action

[0061] Where M and C are the mass matrix and damping matrix of the overall structure, respectively, and R is the restoring force vector of the structure. and x are the acceleration, velocity and displacement vectors of the structure, respectively. The subscripts N, RE and CE refer to the numerical substructure, rate test substructure and conventional test substructure, respectively. i,g is the seismic wave acceleration record, ι is the impact vector, and i is the integration step, i.e., the number of executions, which is determined by the seismic wave length and the integration time interval selected by the user;

[0062] (2) Use the step-by-step integration method to solve the dynamic equations and obtain the three substructure motion commands of the i-th integration step, namely the displacement x of the numerical substructure i,N , displacement x of the conventional test substructure i,CE The displacement and velocity of the substructure in the rate-type test (x i,RE , );

[0063] (3) The numerical substructure is simulated in the computer to calculate the command x of the i-th integration step i,N , and obtain the numerical substructure partial restoring force R i,N , waiting for the conventional test substructure to be loaded;

[0064] (4) The rate-type test substructure conducts real-time tests in the laboratory and loads the command (x i,RE , ), and obtain the rate-type test substructure restoring force R of the current step i,RE , then restore to the initial state of the rate-type test substructure, that is, the displacement and velocity are 0, and wait for the conventional test substructure to be loaded;

[0065] (5) The conventional test substructure is tested slowly in the laboratory, and the command x of the i-th integration step is loaded slowly. i,CE , get the conventional test substructure restoring force R of the current step i,CE ;

[0066] (6) Substitute the three substructure restoring forces into the dynamic equation of (1);

[0067] (7) Repeat (2) to (6) until the end of the experiment.

[0068] The above description is only a specific implementation case of the present invention, and the implementation only lists the civil engineering field. The method can also be applied to the bridge field, aerospace field, mechanical field, etc.

[0069] As described above, the multi-loading rate hybrid testing method for multiple types of test substructures proposed in this invention innovatively proposes a secondary partitioning strategy for the test substructures, namely, one test substructure is repeatable, while the remaining test substructures are allowed to be damaged and destroyed. This allows for low-cost, high-efficiency, and high-precision performance evaluation of large structures equipped with novel rate-based dampers. Therefore, this method has broad application prospects in civil engineering structures equipped with viscous dampers, magnetorheological dampers, tuned liquid dampers, and tuned mass dampers, bridge structures equipped with seismic isolation bearings, and train-bridge structures.

[0070] It will be easily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-loading rate hybrid test method for multi-type test substructures, characterized by: The research object is divided into two substructures: The first substructure is divided according to the degree of concern for the research object. The most concerned structural part is taken out as the experimental substructure and subjected to physical loading test in the laboratory. The remaining structural parts are taken as numerical substructures and simulated in the computer. The second sub-structure division is based on the degree of dependency of the components in the test sub-structure on the rate. The rate-dependent structural parts are taken out as rate-type test sub-structures, and the remaining structural parts are conventional test sub-structures. The specific test steps are as follows: (1) The dynamic equations of the numerical substructure, conventional test substructure, and rate-dependent test substructure under earthquake action are established as follows: Where M and C are the mass matrix and damping matrix of the overall structure, respectively, and R is the restoring force vector of the structure. and x are the acceleration, velocity and displacement vectors of the structure, respectively. The subscripts N, RE and CE refer to the numerical substructure, rate test substructure and conventional test substructure, respectively. i,g is the seismic wave acceleration record, ι is the impact vector, and i is the integration step; (2) Solve the dynamic equations using the step-by-step integration algorithm to obtain the three substructure motion commands at the i-th integration step, namely, the displacement x of the numerical substructure i,N , displacement x of the conventional test substructure i,CE Displacement and velocity of the substructure in the rate-type test (3) The numerical substructure is simulated in the computer to calculate the command x of the i-th integration step i,N , and obtain the numerical substructure partial restoring force R i,N , waiting for the loading of the conventional test substructure and the rate test substructure; (4) The rate test substructure conducts real-time tests in the laboratory and loads the command for the i-th integration step in real time. Get the rate-type test substructure restoring force R of the current step i,RE , then restore to the initial state of the rate-type test substructure, that is, the displacement and velocity are 0, and wait for the conventional test substructure to be loaded; (5) The conventional test substructure is tested slowly in the laboratory, and the command x of the i-th integration step is loaded slowly. i,CE , get the conventional test substructure restoring force R of the current step i,CE ; (6) Substitute the restoring forces of the three substructures into the dynamic equations of step (1); (7) Repeat steps (2) to (6) until the test is completed.

2. The multi-loading rate hybrid test method for multi-type test substructures according to claim 1 is characterized in that: After two substructure divisions, there are three substructures in total: numerical substructure, conventional test substructure, and rate test substructure; these three substructures work together to complete the dynamic performance evaluation of resilient structures containing rate-dependent components through time domain boundary coordination technology.

3. The multi-loading rate hybrid test method for multi-type test substructures according to claim 1 or 2, characterized in that: The numerical substructure is simulated in a computer, and there is no requirement for the speed of calculation; the conventional test substructure will be damaged and destroyed during the test, and its test type is a slow loading test; the rate test substructure is repeatable, that is, after multiple physical loadings, its physical properties will return to their original state after a period of static state, and its test type is a real-time loading test.

4. The multi-loading rate hybrid test method for multi-type test substructures according to claim 2 is characterized in that: The time domain boundary coordination technology is as follows: the numerical substructure quickly calculates to implement the current command, maintains the current state after completion, and waits for the conventional test substructure and rate test substructure to be loaded; the rate test substructure is loaded in real time to implement the current command, and returns to the original state after completion, waiting for the conventional test substructure to be loaded; the conventional test substructure finally completes the loading task and maintains the current state; at this time, the three types of substructures wait for the command of the next integration step.

5. The multi-loading rate hybrid test method for multi-type test substructures according to claim 4 is characterized in that: The state includes the displacement, velocity and acceleration of the substructure, and the command includes the displacement command, velocity command, acceleration command and force command.

Images