A test method and mechanical model for the shear performance of a variable vertical force seismic isolation rubber bearing

Abstract

This invention relates to the field of seismic isolation and testing methods in civil engineering, and discloses a test method and mechanical model for the shear performance of variable vertical force seismic isolation rubber bearings. The method includes: keeping a first vertical pressure F1 constant, applying a horizontal displacement to the bearing body along a first direction using a horizontal hydraulic servo loader; when the bearing body is loaded to a first displacement X1, gradually and linearly decreasing the first vertical pressure F1 according to the horizontal displacement X2-X1 to a second vertical force F2; keeping the first vertical pressure F1 constant, applying a horizontal displacement to the bearing body along a second direction using a horizontal hydraulic servo loader; when the bearing body is loaded to a third displacement X3, gradually and linearly decreasing the first vertical pressure F1 according to the horizontal displacement X4-X3 to a second vertical force F2; and finally, proposing a shear hardening model for variable vertical force seismic isolation rubber bearings. This invention can provide more accurate test data and more realistically reflect the actual stress state of the seismic isolation bearing during an earthquake.

Description

Technical Field

[0001] This invention relates to the field of seismic isolation and testing methods in civil engineering, and more specifically, to a test method and mechanical model for the shear performance of variable vertical force seismic isolation rubber bearings. Background Technology

[0002] In current engineering practice, the methods for determining the shear performance of seismic isolation rubber bearings mainly rely on testing the horizontal shear performance under a constant vertical load. When designing seismic isolation structures, engineers typically use a simplified "bi-linear" model to characterize the shear performance of the bearings under a constant vertical load. However, during actual earthquakes, the vertical load on the bearings changes with the increase of horizontal shear displacement, and may even shift from compression to tension. This significant fluctuation in vertical load has a crucial impact on the shear performance of the bearings. Unfortunately, current methods for testing the shear performance of seismic isolation bearings do not adequately consider the influence of this vertical load variation. Furthermore, existing testing methods fail to provide an accurate mechanical model to describe the impact of vertical load variations on the shear performance of seismic isolation bearings.

[0003] Currently, the determination of the shear performance of seismic isolation rubber bearings mainly focuses on the horizontal shear performance under constant vertical loads, lacking experimental methods for measuring the shear performance of seismic isolation rubber bearings under varying vertical loads. This is detrimental to the assessment of the horizontal shear performance of seismic isolation rubber bearings under significant changes in vertical loads during seismic loading. When designing seismic isolation structures, the primary basis is the "bi-linear" model for determining horizontal shear performance under constant vertical loads, without considering the influence of shear performance changes under varying vertical tensile and compressive stresses. The stress state of seismic isolation rubber bearings under constant vertical loads differs from that under actual seismic loading, and using the "bi-linear" model based on constant vertical load horizontal shear performance measurements for seismic isolation structure design poses safety risks.

[0004] Therefore, it is necessary to establish a test method and mechanical model for the shear performance of variable vertical force seismic isolation rubber bearings to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a test method and mechanical model for the shear performance of a variable vertical force seismic isolation rubber bearing, aiming to more accurately evaluate the performance of the seismic isolation bearing under actual seismic action.

[0006] In one aspect, the present invention proposes a test method for the shear performance of a variable vertical force seismic isolation rubber bearing, comprising:

[0007] S1. Place the seismic isolation bearing test device in the dedicated test area;

[0008] S2. Use high-strength bolts to fix the upper connecting plate to the lower surface of the upper loading platform, and fix the lower connecting plate to the upper surface of the lower loading platform;

[0009] S3. Apply the first vertical pressure F1 to the seismic isolation bearing body using a vertical servo loader;

[0010] S4. Keeping the first vertical pressure F1 constant, a horizontal displacement is applied to the seismic isolation bearing body along the first direction using a horizontal hydraulic servo loader, loading the seismic isolation bearing body to the first displacement X1; then, the horizontal displacement is further applied to the seismic isolation bearing along the first direction using the horizontal hydraulic servo loader. When the seismic isolation bearing body is loaded from the first displacement X1 to the second displacement X2, the first vertical pressure F1 is gradually and linearly reduced to the second vertical force F2 as the horizontal displacement X2-X1 changes, and the change of the first horizontal force is recorded in real time.

[0011] S5. Unload the horizontal hydraulic servo loader to the zero position along the original loading path, and return the vertical servo loader to the first vertical pressure F1 along the original loading path;

[0012] S6. Keeping the first vertical pressure F1 unchanged, the horizontal hydraulic servo loader is used to apply a horizontal displacement to the seismic isolation bearing body along the second direction, loading the seismic isolation bearing body to the third displacement X3; then the horizontal hydraulic servo loader is used to continue applying a horizontal displacement to the seismic isolation bearing along the second direction. When the seismic isolation bearing body is loaded from the third displacement X3 to the fourth displacement X4, the first vertical pressure F1 is gradually and linearly reduced to the second vertical force F2 as the horizontal displacement X4-X3 changes, and the change of the second horizontal force is recorded in real time.

[0013] S7. Unload the horizontal hydraulic servo loader to the zero position along the original loading path, and return the vertical servo loader to the first vertical pressure F1 along the original loading path;

[0014] S8. Repeat steps S3-S7 for three cycles, collecting horizontal force, horizontal displacement and vertical force in real time during the test.

[0015] S9. Take the horizontal force, horizontal displacement and vertical force recorded in the third cycle to construct a shear hardening model of the variable vertical force seismic isolation rubber bearing, and calculate the shear performance parameters of the seismic isolation bearing based on the variable vertical force seismic isolation rubber bearing shear hardening model.

[0016] Furthermore, the seismic isolation bearing test device includes:

[0017] The seismic isolation bearing body;

[0018] The upper loading platform is vertically positioned at the top of the seismic isolation bearing body;

[0019] The lower loading platform is vertically positioned at the bottom end of the seismic isolation bearing body;

[0020] The first support base is located at the bottom of the lower loading platform;

[0021] The second support is fixedly connected to one end of the first support;

[0022] A vertical servo loader is positioned vertically on top of the upper loading platform;

[0023] A horizontal hydraulic servo loader is arranged horizontally on the side of the lower loading platform near the second support base. One end of the horizontal hydraulic servo loader is connected to the second support base, and the other end of the horizontal hydraulic servo loader is connected to the lower loading platform.

[0024] The upper connecting plate is detachably connected to the lower surface of the upper loading platform;

[0025] The lower connecting plate is detachably connected to the upper surface of the lower loading platform.

[0026] Furthermore, the first direction is opposite to the second direction in the horizontal direction.

[0027] Furthermore, the horizontal force includes the first horizontal force and the second horizontal force;

[0028] The horizontal displacement includes the first displacement X1, the second displacement X2, the third displacement X3, and the fourth displacement X4;

[0029] The vertical force includes a first vertical pressure F1 and a second vertical force F2.

[0030] Furthermore, when calculating the shear performance parameters of the seismic isolation bearing based on the variable vertical force seismic isolation rubber bearing shear hardening model, the following steps are included:

[0031] The first stage is defined as the stiffness k1 of the seismic isolation bearing body before yielding; the second stage is defined as the horizontal stiffness k2 of the seismic isolation bearing body under constant pressure after yielding; the third stage is defined as the horizontal stiffness k3 of the seismic isolation bearing body under vertical force variation after yielding; and the horizontal yield force Q of the seismic isolation bearing body is also defined. The first stage is defined as the stiffness k1 of the seismic isolation bearing body before yielding, obtained according to the following formula:

[0032] k1 = (10-15)k2;

[0033] The horizontal stiffness k2 under constant pressure after the seismic isolation bearing body yields in the second stage is obtained according to the following formula:

[0034]

[0035] The horizontal hardening stiffness k3 under the vertical force change after the yielding of the third-stage seismic isolation bearing body is obtained according to the following formula:

[0036]

[0037] The horizontal yield force Q of the seismic isolation bearing body is obtained according to the following formula:

[0038]

[0039] Where Q1 represents the first horizontal force at the first displacement X1 during the loading process, Q2 represents the first horizontal force at the second displacement X2, Q3 represents the second horizontal force at the third displacement X3 during the loading process, Q4 represents the second horizontal force at the fourth displacement X4, X1 represents the first displacement, X2 represents the second displacement, X3 represents the third displacement, and Qd1 and Qd2 represent the two horizontal forces when the horizontal displacement is zero when a Cartesian coordinate system is constructed with the horizontal displacement recorded in the third cycle as the abscissa and the horizontal force recorded in the third cycle as the ordinate.

[0040] In another aspect, the present invention also proposes a shear hardening model for a variable vertical force seismic isolation rubber bearing, comprising:

[0041] Construct a Cartesian coordinate system with horizontal displacement as the abscissa and horizontal force as the ordinate.

[0042] The first horizontal force Q1 at the first displacement X1, the first horizontal force Q2 at the second displacement X2, the second horizontal force Q3 at the third displacement X3, the second horizontal force Q4 at the fourth displacement X4, the first displacement X1, the second displacement X2, the third displacement X3, and the fourth displacement X4 are plotted in the Cartesian coordinate system to construct a shear hardening model of a variable vertical force isolation rubber bearing; where X3=-X1, X4=-X2;

[0043] The shear hardening model of the variable vertical force isolation rubber bearing is divided into three stages: the first stage, the second stage, and the third stage, and the vertical force F is calculated for each stage.

[0044] Furthermore, the shear hardening model of the variable vertical force isolation rubber bearing is divided into a first stage, a second stage, and a third stage, and the calculation of the vertical force F in each stage includes:

[0045] The vertical force in the first stage is obtained by the following formula:

[0046] F = k1X (X ≤ Xy);

[0047] The vertical force in the second stage is obtained by the following formula:

[0048] F=k2X-k2X1+Q(Xy<X≤X1);

[0049] The vertical force in the third stage is obtained by the following formula:

[0050] F=k3X-(k3-k2)X1-k2Xy+Q(X1<X≤X2);

[0051] k3 = αk2;

[0052] Where k1 is the stiffness of the first-stage isolation bearing body before yielding, k2 is the horizontal stiffness of the second-stage isolation bearing body under constant pressure after yielding, k3 is the horizontal hardening stiffness of the third-stage isolation bearing body under vertical force variation after yielding, Xy is the horizontal displacement, X1 is the first displacement, X2 is the second displacement, Q is the horizontal yield force of the isolation bearing body, and α is the hardening coefficient, calculated based on experimental data.

[0053] Compared with existing technologies, the beneficial effects of the present invention are as follows: the shear performance test method for variable vertical force seismic isolation rubber bearings proposed in the present invention can effectively test the horizontal stiffness of seismic isolation rubber bearings under varying vertical forces. This method can not only provide more accurate test data, but also more realistically reflect the actual stress state of the seismic isolation bearings during an earthquake.

[0054] The variable vertical force seismic isolation rubber bearing shear hardening model proposed in this invention has strong applicability, enabling engineers to fully consider the impact of vertical force variations on shear performance when analyzing seismic isolation structures. This allows engineers to more accurately consider actual stress conditions when designing seismic isolation structures, thus creating seismic isolation bearing structures that better reflect real-world conditions.

[0055] In summary, this invention not only improves the accuracy of shear performance testing of seismic isolation rubber bearings, but also provides engineers with a more scientific design basis, making the design of seismic isolation structures more reasonable, safe and reliable. Attached Figure Description

[0056] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0057] Figure 1 A diagram illustrating the loading device used in the test method for the shear performance of variable vertical force seismic isolation rubber bearings provided in this embodiment of the invention.

[0058] Figure 2The diagram showing the relationship between horizontal displacement and vertical force during the loading process of the variable vertical force seismic isolation rubber bearing shear performance test method provided in this embodiment of the invention;

[0059] Figure 3 The shear trilinear hardening mechanical model of the variable vertical force seismic isolation rubber bearing provided in the embodiments of the present invention;

[0060] Figure 4 This is a flowchart illustrating the test method for the shear performance of variable vertical force seismic isolation rubber bearings provided in an embodiment of the present invention.

[0061] In the figure: 110, first support seat; 120, second support seat; 130, vertical servo loader; 140, upper loading platform; 150, seismic isolation bearing body; 160, lower loading platform; 170, horizontal hydraulic servo loader; 180, upper connecting plate; 190, lower connecting plate. Detailed Implementation

[0062] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0063] See Figure 1 As shown in some embodiments of this application, this embodiment provides a method for testing the shear performance of a variable vertical force seismic isolation rubber bearing, including:

[0064] S1. Place the seismic isolation bearing test device in the dedicated test area;

[0065] S2. The upper connecting plate 180 is fixed to the lower surface of the upper loading platform 140 using high-strength bolts, and the lower connecting plate 190 is fixed to the upper surface of the lower loading platform 160.

[0066] S3. A first vertical pressure F1 is applied to the seismic isolation bearing body 150 using a vertical servo loader 130;

[0067] S4. Keeping the first vertical pressure F1 constant, the horizontal hydraulic servo loader 170 applies a horizontal displacement to the seismic isolation bearing body 150 along the first direction, loading the seismic isolation bearing body 150 to the first displacement X1; then the horizontal hydraulic servo loader 170 continues to apply a horizontal displacement to the seismic isolation bearing along the first direction. When the seismic isolation bearing body 150 is loaded from the first displacement X1 to the second displacement X2, the first vertical pressure F1 is gradually and linearly reduced to the second vertical force F2 as the horizontal displacement X2-X1 changes, and the change of the first horizontal force is recorded in real time.

[0068] S5. Unload the horizontal hydraulic servo loader 170 to the zero position along the original loading path, and return the vertical servo loader 130 to the first vertical pressure F1 along the original loading path.

[0069] S6. Keeping the first vertical pressure F1 constant, the horizontal hydraulic servo loader 170 is used to apply a horizontal displacement to the seismic isolation bearing body 150 along the second direction, loading the seismic isolation bearing body 150 to the third displacement X3; then the horizontal hydraulic servo loader 170 is used to continue applying a horizontal displacement to the seismic isolation bearing along the second direction. When the seismic isolation bearing body 150 is loaded from the third displacement X3 to the fourth displacement X4, the first vertical pressure F1 is gradually reduced linearly with the change of the horizontal displacement X4-X3 to the second vertical force F2, and the change of the second horizontal force is recorded in real time.

[0070] S7. Unload the horizontal hydraulic servo loader 170 to the zero position along the original loading path, and return the vertical servo loader 130 to the first vertical pressure F1 along the original loading path.

[0071] S8. Repeat steps S3-S7 for three cycles, collecting horizontal force, horizontal displacement and vertical force in real time during the test.

[0072] S9. Take the horizontal force, horizontal displacement and vertical force recorded in the third cycle to construct a shear hardening model of the variable vertical force seismic isolation rubber bearing, and calculate the shear performance parameters of the seismic isolation bearing based on the shear hardening model of the variable vertical force seismic isolation rubber bearing.

[0073] In this embodiment, the seismic isolation bearing testing device includes: a seismic isolation bearing body 150; an upper loading platform 140, vertically positioned at the top of the seismic isolation bearing body 150; a lower loading platform 160, vertically positioned at the bottom of the seismic isolation bearing body 150; a first support 110, positioned at the bottom of the lower loading platform 160; a second support 120, fixedly connected to one end of the first support 110; a vertical servo loader 130, vertically positioned at the top of the upper loading platform 140; a horizontal hydraulic servo loader 170, horizontally positioned on the side of the lower loading platform 160 near the second support 120, with one end of the horizontal hydraulic servo loader 170 connected to the second support 120 and the other end connected to the lower loading platform 160; an upper connecting plate 180, detachably connected to the lower surface of the upper loading platform 140; and a lower connecting plate 190, detachably connected to the upper surface of the lower loading platform 160.

[0074] As can be seen, the variable vertical force seismic isolation rubber bearing shear performance test method provided in this embodiment can simulate the stress situation of the seismic isolation bearing under actual seismic loading by precisely controlling the action of the loader during the test. This simulation includes not only horizontal forces but also changes in vertical forces, thus enabling a more comprehensive evaluation of the seismic isolation bearing's performance. This method can obtain the stiffness changes of the seismic isolation bearing at different stress stages, providing more detailed data support for engineering design.

[0075] In this embodiment, the first direction and the second direction are opposite to each other in the horizontal direction.

[0076] In this embodiment, the horizontal force includes a first horizontal force and a second horizontal force; the horizontal displacement includes a first displacement X1, a second displacement X2, a third displacement X3 and a fourth displacement X4; and the vertical force includes a first vertical pressure F1 and a second vertical force F2.

[0077] As can be seen, the above steps ensure that the shear performance of the seismic isolation bearing is comprehensively tested during the experiment. Furthermore, by constructing a shear hardening model of the variable vertical force seismic isolation rubber bearing, the performance of the seismic isolation bearing under cyclic loading can be visually observed, thereby evaluating its response under actual seismic loading.

[0078] Specifically, when calculating the shear performance parameters of the seismic isolation bearing based on the variable vertical force seismic isolation rubber bearing shear hardening model, the following steps are included:

[0079] The first stage is defined as the stiffness k1 of the seismic isolation bearing body before yielding; the second stage is defined as the horizontal stiffness k2 of the seismic isolation bearing body under constant pressure after yielding; the third stage is defined as the horizontal stiffness k3 of the seismic isolation bearing body under vertical force variation after yielding; and the horizontal yield force Q of the seismic isolation bearing body is also defined. The first stage is defined as the stiffness k1 of the seismic isolation bearing body before yielding, obtained according to the following formula:

[0080] k1 = (10-15)k2;

[0081] The horizontal stiffness k2 under constant pressure after the seismic isolation bearing body yields in the second stage is obtained according to the following formula:

[0082]

[0083] The horizontal hardening stiffness k3 under the vertical force change after the yielding of the third-stage seismic isolation bearing body is obtained according to the following formula:

[0084]

[0085] The horizontal yield force Q of the seismic isolation bearing body is obtained according to the following formula:

[0086]

[0087] Where Q1 represents the first horizontal force at the first displacement X1 during the loading process, Q2 represents the first horizontal force at the second displacement X2, Q3 represents the second horizontal force at the third displacement X3 during the loading process, Q4 represents the second horizontal force at the fourth displacement X4, X1 represents the first displacement, X2 represents the second displacement, X3 represents the third displacement, and Qd1 and Qd2 represent the two horizontal forces when the horizontal displacement is zero when a Cartesian coordinate system is constructed with the horizontal displacement recorded in the third cycle as the abscissa and the horizontal force recorded in the third cycle as the ordinate.

[0088] As can be seen, the shear performance parameters reflect the stiffness variation of the seismic isolation bearing under different displacements. The calculated shear performance parameters ki (i=1,2,3) can be used to evaluate the shear deformation capacity of the seismic isolation bearing under seismic loading, providing a scientific basis for its design and selection. Furthermore, through multiple cyclic loading, the performance degradation of the seismic isolation bearing during long-term use can be simulated, ensuring its reliability and safety in practical applications. Ultimately, the experimental method and mechanical model provided by this invention not only improve the accuracy of seismic isolation bearing performance evaluation but also provide strong technical support for the optimized design and engineering application of seismic isolation bearings.

[0089] See Figure 2 As shown in some embodiments of this application, this embodiment provides a shear hardening model for a variable vertical force seismic isolation rubber bearing, including:

[0090] Construct a Cartesian coordinate system with horizontal displacement as the abscissa and horizontal force as the ordinate.

[0091] The first horizontal force Q1 at the first displacement X1, the first horizontal force Q2 at the second displacement X2, the second horizontal force Q3 at the third displacement X3, the second horizontal force Q4 at the fourth displacement X4, the first displacement X1, the second displacement X2, the third displacement X3, and the fourth displacement X4 are plotted in a Cartesian coordinate system to construct a shear hardening model of a variable vertical force isolation rubber bearing; where X3=-X1, X4=-X2;

[0092] The shear hardening model of the variable vertical force isolation rubber bearing is divided into three stages: the first stage, the second stage, and the third stage, and the vertical force F is calculated for each stage.

[0093] Specifically, the shear hardening model of the variable vertical force isolation rubber bearing is divided into three stages: the first stage, the second stage, and the third stage. The calculation of the vertical force F for each stage includes:

[0094] The vertical force in the first stage is obtained by the following formula:

[0095] F = k1X (X ≤ Xy);

[0096] The vertical force in the second stage is obtained by the following formula:

[0097] F=k2X-k2X1+Q(Xy<X≤X1);

[0098] The vertical force in the third stage is obtained by the following formula:

[0099] F=k3X-(k3-k2)X1-k2Xy+Q(X1<X≤X2);

[0100] k3 = αk2;

[0101] Where k1 is the stiffness of the first-stage isolation bearing body before yielding, k2 is the horizontal stiffness of the second-stage isolation bearing body under constant pressure after yielding, k3 is the horizontal hardening stiffness of the third-stage isolation bearing body under vertical force variation after yielding, Xy is the horizontal displacement, X1 is the first displacement, X2 is the second displacement, Q is the horizontal yield force of the isolation bearing body, and α is the hardening coefficient, calculated based on experimental data.

[0102] Understandably, the hardening coefficient α reflects the trend of horizontal stiffness change of the seismic isolation bearing after yielding with varying vertical force. In the first stage, when the displacement X is less than or equal to the yield displacement Xy, the horizontal stiffness of the seismic isolation bearing remains unchanged, and the vertical force F is proportional to the displacement X. In the second stage, when the displacement X is greater than the yield displacement Xy but less than or equal to the first displacement X1, the calculation of the vertical force F considers the contribution of the horizontal stiffness k2 under constant pressure after the seismic isolation bearing body yields in the second stage and the contribution of the stiffness k1 of the seismic isolation bearing body before yielding in the first stage to the horizontal force Q. In the third stage, when the displacement X is greater than the first displacement X1 but less than or equal to the second displacement X2, the calculation of the vertical force F needs to consider the horizontal hardening stiffness k3 under the change of vertical force after yielding, the difference between k3 and k2, and the contribution of the stiffness k1 of the seismic isolation bearing body before yielding in the first stage to the horizontal yield force Q of the seismic isolation bearing body. Through such phased calculations, the mechanical behavior of seismic isolation bearings under different stress stages can be simulated more accurately, providing a more precise theoretical basis for the design and engineering application of seismic isolation bearings. Ultimately, the combination of this experimental method and mechanical model can not only evaluate the shear performance of seismic isolation bearings but also predict their performance changes during long-term use, providing strong technical support for the optimized design and safe application of seismic isolation bearings.

[0103] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0105] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0106] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A test method for the shear performance of a variable vertical force seismic isolation rubber bearing, characterized in that, include: S1. Place the seismic isolation bearing test device in the dedicated test area; S2. Use high-strength bolts to fix the upper connecting plate to the lower surface of the upper loading platform, and fix the lower connecting plate to the upper surface of the lower loading platform; S3. Apply the first vertical pressure F1 to the seismic isolation bearing body using a vertical servo loader; S4. Keeping the first vertical pressure F1 constant, a horizontal displacement is applied to the seismic isolation bearing body along the first direction using a horizontal hydraulic servo loader, loading the seismic isolation bearing body to the first displacement X1; then, the horizontal displacement is further applied to the seismic isolation bearing along the first direction using the horizontal hydraulic servo loader. When the seismic isolation bearing body is loaded from the first displacement X1 to the second displacement X2, the first vertical pressure F1 is gradually and linearly reduced to the second vertical force F2 as the horizontal displacement X2-X1 changes, and the change of the first horizontal force is recorded in real time. S5. Unload the horizontal hydraulic servo loader to the zero position along the original loading path, and return the vertical servo loader to the first vertical pressure F1 along the original loading path; S6. Keeping the first vertical pressure F1 unchanged, the horizontal hydraulic servo loader is used to apply a horizontal displacement to the seismic isolation bearing body along the second direction, loading the seismic isolation bearing body to the third displacement X3; then the horizontal hydraulic servo loader is used to continue applying a horizontal displacement to the seismic isolation bearing along the second direction. When the seismic isolation bearing body is loaded from the third displacement X3 to the fourth displacement X4, the first vertical pressure F1 is gradually and linearly reduced to the second vertical force F2 as the horizontal displacement X4-X3 changes, and the change of the second horizontal force is recorded in real time. S7. Unload the horizontal hydraulic servo loader to the zero position along the original loading path, and return the vertical servo loader to the first vertical pressure F1 along the original loading path; S8. Repeat steps S3-S7 for three cycles, collecting horizontal force, horizontal displacement and vertical force in real time during the test. S9. Take the horizontal force, horizontal displacement and vertical force recorded in the third cycle to construct a shear hardening model of the variable vertical force seismic isolation rubber bearing, and calculate the shear performance parameters of the seismic isolation bearing based on the variable vertical force seismic isolation rubber bearing shear hardening model.

2. The test method for shear performance of variable vertical force seismic isolation rubber bearing according to claim 1, characterized in that, The seismic isolation bearing test device includes: The seismic isolation bearing body; The upper loading platform is vertically positioned at the top of the seismic isolation bearing body; The lower loading platform is vertically positioned at the bottom end of the seismic isolation bearing body; The first support base is located at the bottom of the lower loading platform; The second support is fixedly connected to one end of the first support; A vertical servo loader is positioned vertically on top of the upper loading platform; A horizontal hydraulic servo loader is arranged horizontally on the side of the lower loading platform near the second support base. One end of the horizontal hydraulic servo loader is connected to the second support base, and the other end of the horizontal hydraulic servo loader is connected to the lower loading platform. The upper connecting plate is detachably connected to the lower surface of the upper loading platform; The lower connecting plate is detachably connected to the upper surface of the lower loading platform.

3. The test method for shear performance of variable vertical force seismic isolation rubber bearing according to claim 1, characterized in that, The first direction is opposite to the second direction in the horizontal direction.

4. The test method for shear performance of variable vertical force seismic isolation rubber bearing according to claim 1, characterized in that, The horizontal force includes the first horizontal force and the second horizontal force; The horizontal displacement includes the first displacement X1, the second displacement X2, the third displacement X3, and the fourth displacement X4; The vertical force includes a first vertical pressure F1 and a second vertical force F2.

5. The test method for shear performance of variable vertical force seismic isolation rubber bearing according to claim 1, characterized in that, When calculating the shear performance parameters of the seismic isolation bearing based on the variable vertical force seismic isolation rubber bearing shear hardening model, the following are included: The first stage is defined as the stiffness k1 of the seismic isolation bearing body before yielding; the second stage is defined as the horizontal stiffness k2 of the seismic isolation bearing body under constant pressure after yielding; the third stage is defined as the horizontal stiffness k3 of the seismic isolation bearing body under vertical force variation after yielding; and the horizontal yield force Q of the seismic isolation bearing body is also defined. The first stage is defined as the stiffness k1 of the seismic isolation bearing body before yielding, obtained according to the following formula: k1 = (10-15)k2; The horizontal stiffness k2 under constant pressure after the seismic isolation bearing body yields in the second stage is obtained according to the following formula: ; The horizontal hardening stiffness k3 under the vertical force change after the yielding of the third-stage seismic isolation bearing body is obtained according to the following formula: ; The horizontal yield force Q of the seismic isolation bearing body is obtained according to the following formula: ; Where Q1 represents the first horizontal force at the first displacement X1 during the loading process, Q2 represents the first horizontal force at the second displacement X2, Q3 represents the second horizontal force at the third displacement X3 during the loading process, Q4 represents the second horizontal force at the fourth displacement X4, X1 represents the first displacement, X2 represents the second displacement, X3 represents the third displacement, and Qd1 and Qd2 represent the two horizontal forces when the horizontal displacement is zero when a Cartesian coordinate system is constructed with the horizontal displacement recorded in the third cycle as the abscissa and the horizontal force recorded in the third cycle as the ordinate.

6. A shear hardening model for a variable vertical force seismic isolation rubber bearing, applied in the test method for the shear performance of a variable vertical force seismic isolation rubber bearing as described in any one of claims 1-5, characterized in that, include: Construct a Cartesian coordinate system with horizontal displacement as the abscissa and horizontal force as the ordinate. The first horizontal force Q1 at the first displacement X1, the first horizontal force Q2 at the second displacement X2, the second horizontal force Q3 at the third displacement X3, the second horizontal force Q4 at the fourth displacement X4, the first displacement X1, the second displacement X2, the third displacement X3, and the fourth displacement X4 are plotted in the Cartesian coordinate system to construct a shear hardening model of a variable vertical force isolation rubber bearing; where X3=-X1, X4=-X2; The shear hardening model of the variable vertical force isolation rubber bearing is divided into three stages: the first stage, the second stage, and the third stage, and the vertical force F is calculated for each stage.

7. The shear hardening model of the variable vertical force seismic isolation rubber bearing according to claim 6, characterized in that, The shear hardening model of the variable vertical force isolation rubber bearing is divided into three stages: a first stage, a second stage, and a third stage. The calculation of the vertical force F in each stage includes: The vertical force in the first stage is obtained by the following formula: F = k1X (X ≤ Xy); The vertical force in the second stage is obtained by the following formula: F=k2X-k2X1+Q(Xy<X≤X1); The vertical force in the third stage is obtained by the following formula: F=k3X-(k3-k2)X1-k2Xy+Q(X1<X≤X2); k3 = αk2; Where k1 is the stiffness of the first-stage isolation bearing body before yielding, k2 is the horizontal stiffness of the second-stage isolation bearing body under constant pressure after yielding, k3 is the horizontal hardening stiffness of the third-stage isolation bearing body under vertical force variation after yielding, Xy is the horizontal displacement, X1 is the first displacement, X2 is the second displacement, Q is the horizontal yield force of the isolation bearing body, and α is the hardening coefficient, calculated based on experimental data.

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