A clamp for micro-isolation bearing pressurized shear test and a method of using the same

Abstract

The present application relates to a kind of clamp for micro-isolation bearing pressurized shear test and its use method, the clamp is installed on electronic universal testing machine when using, for the pressurized shear test to micro-isolation bearing, the clamp includes reversing loading component and confining pressure component, the reversing loading component is by the micro-isolation bearing test piece of first reversing loading plate and second reversing loading plate between placing to be tested, the confining pressure component is by first roller link, second roller link, third roller link and fourth roller link form confining pressure structure, for the confining pressure force of first reversing loading plate and second reversing loading plate is applied, first reversing loading plate and second reversing loading plate and confining pressure structure cooperation convert the axial tension of electronic universal testing machine into shear force, to carry out pressurized shear test to the micro-isolation bearing test piece to be tested.Compared with prior art, the present application has the advantages of low manufacturing cost, pressure uniform, small error etc..

Description

Technical Field

[0001] This invention relates to the field of mechanical testing technology, and in particular to a fixture and method for using a micro-isolation bearing under pressure shear test. Background Technology

[0002] Rubber bearings are widely used in seismic isolation design for ground-based buildings, bridges, and other structures. These include natural rubber bearings (NRB), lead-core rubber bearings (LRB), and high-damping rubber bearings (HDR). As seismic isolation devices, various rubber bearings are installed between the foundation and the superstructure (or between two floors) to keep the structure's natural period away from the dominant period of the seismic motion, thereby reducing the seismic response of the superstructure. Seismic isolation bearings often bear the gravity load of the superstructure, and under seismic loading, they will undergo shear deformation under high axial compression. Therefore, it is necessary to determine the shear performance of seismic isolation bearings under high axial compression, such as shear modulus and allowable shear angle, generally using a compression-shear testing machine (e.g., CN202210305671). In shaking table model tests of various seismic isolation structures, to meet the similarity ratio design requirements, a miniature seismic isolation bearing much smaller than conventional sizes is often used. However, due to its small size, it does not meet the size requirements of conventional compression-shear testing machines and cannot be tested using these machines.

[0003] Electro-hydraulic servo universal testing machines are commonly used for testing the mechanical properties of materials and components. They can perform conventional tensile and compressive property tests and can also perform pressureless shear performance tests using simple fixtures. However, for micro-isolation bearings, testing shear performance under pressureless conditions does not conform to the actual stress conditions of the component and generates additional bending moments and torques, causing the bearing to tear or delaminate before reaching the allowable shear angle, thus failing to achieve the test objective. Furthermore, current electro-hydraulic servo universal testing machines cannot perform pressure shear performance tests on bearings. Therefore, a fixture is needed that can be used to perform pressure shear tests on micro-isolation bearings using an electro-hydraulic servo universal testing machine. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing a fixture and its method of use for pressure shear testing of micro-isolation bearings.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A fixture for performing compressive shear tests on microseismic isolation bearings is disclosed. The fixture is mounted on an electronic universal testing machine for conducting compressive shear tests on the microseismic isolation bearings. The fixture includes a reversing loading assembly and a confining pressure assembly.

[0007] The reversing loading assembly includes a first reversing loading plate and a second reversing loading plate. The first reversing loading plate is connected to the upper clamp of the testing machine, and the second reversing loading plate is connected to the lower clamp of the testing machine. The first and second reversing loading plates are arranged opposite to each other and are parallel to the axial direction of the testing machine. The space between the first and second reversing loading plates is used to place the miniature seismic isolation bearing specimen to be tested.

[0008] The confining pressure assembly includes a first roller connecting rod, a second roller connecting rod, a third roller connecting rod, and a fourth roller connecting rod. The first and second roller connecting rods are directly connected to the first reversing loading plate, and the third and fourth roller connecting rods are directly connected to the second reversing loading plate. The first roller connecting rod passing through the first reversing loading plate is connected to the third roller connecting rod passing through the second reversing loading plate, and the second roller connecting rod passing through the first reversing loading plate is connected to the fourth roller connecting rod passing through the second reversing loading plate. The first, second, third, and fourth roller connecting rods form a confining pressure structure for applying confining pressure to the first and second reversing loading plates.

[0009] The first and second reversing loading plates, in conjunction with the confining pressure structure, convert the axial tensile force of the electronic universal testing machine into shear force, thereby conducting a pressure shear test on the micro-isolation bearing specimen to be tested.

[0010] In one embodiment of the present invention, the reversing loading assembly further includes test piece bolts, a first shim, and a second shim. The first shim is fixed to the first reversing loading plate by four test piece bolts, and the second shim is fixed to the second reversing loading plate by four test piece bolts. The first and second shims are used to fix the micro-isolation bearing test specimen to be tested between the first and second reversing loading plates. The test piece bolts are used to fix the first or second shim, providing stable shear loading conditions. The gap between the first and second reversing loading plates can be adjusted by using first and second shims of different thicknesses. The thickness or number of the first and second shims can be adjusted as needed to meet the minimum gap requirement between the first and second reversing loading plates.

[0011] In one embodiment of the present invention, the first reversing loading plate and the second reversing loading plate are steel plates with a large thickness. By using steel plates with a large thickness to manufacture the first reversing loading plate and the second reversing loading plate, a large stiffness is achieved, providing stable shear loading conditions for the micro seismic isolation bearing specimen to be tested.

[0012] In one embodiment of the present invention, the first reversing loading plate and the second reversing loading plate are provided with bolt holes. The test specimen bolt passes through the bolt holes and connects with the first shim or the second shim. The position of the bolt holes can be adjusted as needed to meet the requirement of minimum gap between the first reversing loading plate and the second reversing loading plate. The test specimen bolt is used to fix the test specimen between the first reversing loading plate and the second reversing loading plate.

[0013] In one embodiment of the present invention, the confining pressure assembly includes two first roller connecting rods, two second roller connecting rods, two third roller connecting rods, and two fourth roller connecting rods. The two first roller connecting rods and the two second roller connecting rods are respectively disposed on both sides of the first reversing loading plate, and the two third roller connecting rods and the two fourth roller connecting rods are respectively disposed on both sides of the second reversing loading plate.

[0014] Two first roller connecting rods, two second roller connecting rods, two third roller connecting rods, and two fourth roller connecting rods are all rollers at one end. The rollers are in direct contact with the first reversing loading plate or the second reversing loading plate, serving as the application point of the confining pressure. The rollers apply four-point pressure to the first reversing loading plate or the second reversing loading plate, and the friction is reduced by lubrication of the contact surface.

[0015] In one embodiment of the present invention, the confining pressure assembly further includes a straight connecting plate bolt, two first straight connecting plates, and two second straight connecting plates. The first roller connecting rod, the first straight connecting plate, the second straight connecting plate, and the third roller connecting rod are sequentially connected and fixed by the straight connecting plate bolt. The second roller connecting rod, the first straight connecting plate, the second straight connecting plate, and the fourth roller connecting rod are sequentially connected and fixed by the straight connecting plate bolt. The first and second straight connecting plates are used to connect the roller connecting rods on the same side of the first reversing loading plate and the second reversing loading plate, and are fixed by the straight connecting plate bolt, so that the eight roller connecting rods form a whole, so that the pressure is stable during the test and the confining pressure device is prevented from deforming or shifting.

[0016] In one embodiment of the present invention, the confining pressure assembly further includes two overlapping curved connecting pieces and two overlapping bolts. One end of the overlapping curved connecting piece is fixed to the first reversing loading plate by the overlapping bolts, and the other end of the overlapping curved connecting piece is connected to the third roller connecting rod. The overlapping curved connecting piece is used to prevent the confining pressure assembly from slipping during shear loading.

[0017] In one embodiment of the present invention, the confining pressure assembly further includes two first pressure-bearing curved connecting plates, two second pressure-bearing curved connecting plates, two third pressure-bearing curved connecting plates, and two fourth pressure-bearing curved connecting plates. The two first pressure-bearing curved connecting plates are sequentially disposed at the lower ends of the first roller connecting rods and simultaneously connected to the two first roller connecting rods. The two second pressure-bearing curved connecting plates are sequentially disposed at the lower ends of the second roller connecting rods and simultaneously connected to the two second roller connecting rods. The two third pressure-bearing curved connecting plates are sequentially disposed at the upper ends of the third roller connecting rods and simultaneously connected to the two third roller connecting rods. The two fourth pressure-bearing curved connecting plates are sequentially disposed at the upper ends of the fourth roller connecting rods and simultaneously connected to the two fourth roller connecting rods. The multiple pressure-bearing curved connecting plates stabilize the pressure during the test.

[0018] In one embodiment of the present invention, the confining pressure assembly further includes curved connecting plate bolts and roller connecting rod bolts. Two first pressure curved connecting plates are fixed to each other by curved connecting plate bolts, two second pressure curved connecting plates are fixed to each other by curved connecting plate bolts, two third pressure curved connecting plates are fixed to each other by curved connecting plate bolts, and two fourth pressure curved connecting plates are fixed to each other by curved connecting plate bolts. The curved connecting plate bolts are used to prevent the confining pressure assembly from deforming or shifting.

[0019] Two first pressure-bending connecting plates are sequentially fixed to the lower end of the first roller connecting rod by roller connecting rod bolts. Two second pressure-bending connecting plates are sequentially fixed to the lower end of the second roller connecting rod by roller connecting rod bolts. Two third pressure-bending connecting plates are sequentially fixed to the upper end of the third roller connecting rod by roller connecting rod bolts. Two fourth pressure-bending connecting plates are sequentially fixed to the upper end of the fourth roller connecting rod by roller connecting rod bolts. The roller connecting rod bolts fix different roller connecting rods and different pressure-bending connecting plates at two points to prevent deformation or misalignment of the confining pressure device.

[0020] Furthermore, the present invention also provides a method for using a fixture for a compressive shear test of a micro seismic isolation bearing, the specific steps of which are as follows:

[0021] S1. First, the compression loading function of the electronic universal testing machine is used to compress and load the micro seismic isolation bearing specimen, the first reversing loading plate and the second reversing loading plate to the specified pressure, thereby providing pre-pressure to the micro seismic isolation bearing specimen to be tested.

[0022] S2. Then, under the pre-pressure described in step S1, the confining pressure assembly is installed, and the confining pressure assembly is overlapped with the first reversing loading plate and the second reversing loading plate. At the same time, the micro-seismic isolation bearing specimen to be tested is fixed between the confining pressure assembly. Then, the micro-seismic isolation bearing specimen to be tested is unloaded from the first reversing loading plate and the second reversing loading plate. Thus, during the unloading and rebound process of the micro-seismic isolation bearing specimen to be tested, the confining pressure assembly generates confining pressure, forming the pressure required for the pressure shear test.

[0023] S3. Then, using the tensile loading function of the electronic universal testing machine, the two ends of the first reversing loading plate and the second reversing loading plate are clamped at the upper or lower chuck of the electronic universal testing machine and tensile loading is performed. At this time, the first reversing loading plate and the second reversing loading plate cooperate with the confining pressure structure to convert the axial tensile force generated by the electronic universal testing machine into the shear force required for the test of the micro-vibration isolation bearing specimen.

[0024] S4. During the loading process, the confining pressure assembly forms a symmetrical four-point confining pressure loading on the first reversing loading plate and the second reversing loading plate through the rollers. Since the rollers and the surfaces of the first reversing loading plate and the second reversing loading plate are lubricated, the confining pressure assembly can achieve stable confining pressure loading on the micro-isolation bearing specimen under almost no friction, thereby meeting the pressure shear test conditions.

[0025] S5. Finally, a unidirectional, cyclic compression shear test is conducted on the micro-isolation bearing specimen to be tested. The required mechanical parameters for shear stiffness and shear angle of the micro-isolation bearing specimen to be tested are calculated based on the slope of the force-displacement curve. The test is then completed.

[0026] Further, in step S3, the shear force (shear force) means: "shear" is the phenomenon of relative displacement deformation of the cross section of a material along the direction of the action of a pair of closely spaced, equal in magnitude and opposite in direction of the transverse external forces (i.e. forces perpendicular to the action surface); the force that can cause shear deformation of the material is called shear force or shear force, and the cross section that undergoes shear deformation is called the shear surface.

[0027] Compared with the prior art, the advantages of the present invention are as follows:

[0028] (1) The micro-vibration isolation bearing compression-shear test is carried out using the common testing instrument, the electronic universal testing machine, which makes up for the deficiency that the conventional compression-shear testing machine cannot test small-sized specimens. The cost of the test fixture of the present invention is reduced by more than 90% compared with the modification and manufacturing cost of the compression-shear testing machine.

[0029] (2) Accurate and uniform pressure application: The pre-pressure is applied to the specimen through the compression loading function of the electronic universal testing machine, and the pre-pressure is locked by the confining pressure assembly to form confining pressure, which ensures the accuracy of the pressure. The four-point confining pressure is applied to the reversing loading plate by the roller, which ensures the uniformity and symmetry of the pressure.

[0030] (3) Accurate measurement of compression and shear performance: The confining pressure is applied by rollers and the contact surface is lubricated so that the influence of the confining pressure component on the shear stiffness of the micro-isolation bearing specimen can be ignored. The measured data shows that the error is less than 1%, which fully meets the design reference requirements. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a front view of the first reversing loading plate;

[0033] Figure 3 This is a side view of the first reversing loading plate;

[0034] Figure 4 This is a top view of the first reversing loading plate;

[0035] Figure 5 This is a schematic diagram of the structure of the first gasket;

[0036] Figure 6 This is a front view of the first roller connecting rod;

[0037] Figure 7 This is a side view of the first roller connecting rod;

[0038] Figure 8 This is a top view of the first roller connecting rod;

[0039] Figure 9 This is a schematic diagram of the structure of the first pressure-bearing connecting piece;

[0040] Figure 10 This is a schematic diagram of the structure of the first straight connecting piece;

[0041] Figure 11 This is a flowchart of the experiment conducted on the fixture of the present invention.

[0042] Explanation of reference numerals: 1. First reversing loading plate; 2. Second reversing loading plate; 3. First roller connecting rod; 4. Second roller connecting rod; 5. Third roller connecting rod; 6. Fourth roller connecting rod; 7. First pressure curved connecting piece; 8. Second pressure curved connecting piece; 9. Third pressure curved connecting piece; 10. Fourth pressure curved connecting piece; 11. Overlapping curved connecting piece; 12. First straight connecting piece; 13. Second straight connecting piece; 14. First gasket; 15. Second gasket; 16. Specimen bolt; 17. Curved connecting piece bolt; 18. Straight connecting piece bolt; 19. Roller connecting rod bolt; 20. Overlapping bolt; 21. Upper chuck of testing machine; 22. Lower chuck of testing machine. Detailed Implementation

[0043] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0046] Example

[0047] See Figures 1 to 10 This embodiment provides a fixture for a compressive shear test on a micro seismic isolation bearing. The fixture is mounted on an electronic universal testing machine for performing compressive shear tests on the micro seismic isolation bearing. The fixture includes a reversing loading assembly and a confining pressure assembly.

[0048] The reversing loading assembly includes a first reversing loading plate 1 and a second reversing loading plate 2. The first reversing loading plate 1 is connected to the upper clamp 21 of the testing machine, and the second reversing loading plate 2 is connected to the lower clamp 22 of the testing machine. The first reversing loading plate 1 and the second reversing loading plate 2 are arranged opposite to each other and are parallel to the axial direction of the testing machine. The space between the first reversing loading plate 1 and the second reversing loading plate 2 is used to place the miniature seismic isolation bearing specimen to be tested.

[0049] The confining pressure assembly includes a first roller connecting rod 3, a second roller connecting rod 4, a third roller connecting rod 5, and a fourth roller connecting rod 6. The first roller connecting rod 3 and the second roller connecting rod 4 are directly connected to the first reversing loading plate 1, and the third roller connecting rod 5 and the fourth roller connecting rod 6 are directly connected to the second reversing loading plate 2. The first roller connecting rod 3, passing through the first reversing loading plate 1, connects to the third roller connecting rod 5, which passes through the second reversing loading plate 2. The second roller connecting rod 4, passing through the first reversing loading plate 1, connects to the fourth roller connecting rod 6, which passes through the second reversing loading plate 2. The first roller connecting rod 3, the second roller connecting rod 4, the third roller connecting rod 5, and the fourth roller connecting rod 6 form a confining pressure structure for applying confining pressure to the first reversing loading plate 1 and the second reversing loading plate 2.

[0050] The first reversing loading plate 1 and the second reversing loading plate 2 cooperate with the confining pressure structure to convert the axial tensile force of the electronic universal testing machine into shear force, thereby conducting a pressure shear test on the micro-isolation bearing specimen to be tested.

[0051] In this embodiment, the reversing loading assembly further includes specimen bolts 16, a first shim 14, and a second shim 15. The first shim 14 is fixed to the first reversing loading plate 1 by four specimen bolts 16, and the second shim 15 is fixed to the second reversing loading plate 2 by four specimen bolts 16. The first shim 14 and the second shim 15 are used to fix the micro-seismic isolation bearing specimen to be tested between the first reversing loading plate 1 and the second reversing loading plate 2. The specimen bolts 16 are used to fix the first shim 14 or the second shim 15, providing stable shear loading conditions. The gap between the first reversing loading plate 1 and the second reversing loading plate 2 can be adjusted by using the first shim 14 and the second shim 15 of different thicknesses. The thickness or number of the first shim 14 and the second shim 15 can be adjusted as needed to meet the minimum gap requirement between the first reversing loading plate 1 and the second reversing loading plate 2.

[0052] In this embodiment, the first reversing loading plate 1 and the second reversing loading plate 2 are steel plates with a large thickness. By using steel plates with a large thickness to manufacture the first reversing loading plate 1 and the second reversing loading plate 2, they achieve greater stiffness and provide stable shear loading conditions for the micro seismic isolation bearing specimen to be tested.

[0053] In this embodiment, the first reversing loading plate 1 and the second reversing loading plate 2 are provided with bolt holes. The test piece bolt 16 passes through the bolt holes and connects with the first washer 14 or the second washer 15. The position of the bolt holes can be adjusted as needed to meet the requirement of minimum gap between the first reversing loading plate 1 and the second reversing loading plate 2. The test piece bolt 16 is used to fix the test piece between the first reversing loading plate 1 and the second reversing loading plate 2.

[0054] In this embodiment, the confining pressure assembly includes two first roller connecting rods 3, two second roller connecting rods 4, two third roller connecting rods 5, and two fourth roller connecting rods 6. The two first roller connecting rods 3 and the two second roller connecting rods 4 are respectively disposed on both sides of the first reversing loading plate 1, and the two third roller connecting rods 5 and the two fourth roller connecting rods 6 are respectively disposed on both sides of the second reversing loading plate 2.

[0055] Two first roller connecting rods 3, two second roller connecting rods 4, two third roller connecting rods 5, and two fourth roller connecting rods 6 each have a roller at one end. The rollers are in direct contact with the first reversing loading plate 1 or the second reversing loading plate 2, serving as the application point of the confining pressure. The rollers apply four-point pressure on the first reversing loading plate 1 or the second reversing loading plate 2, and the friction is reduced by lubricating the contact surface.

[0056] In this embodiment, the confining pressure assembly further includes a straight connecting bolt 18, two first straight connecting plates 12, and two second straight connecting plates 13. The first roller connecting rod 3, the first straight connecting plate 12, the second straight connecting plate 13, and the third roller connecting rod 5 are sequentially connected and fixed by the straight connecting bolt 18. The second roller connecting rod 4, the first straight connecting plate 12, the second straight connecting plate 13, and the fourth roller connecting rod 6 are sequentially connected and fixed by the straight connecting bolt 18. The first straight connecting plate 12 and the second straight connecting plate 13 are used to connect the roller connecting rods on the same side of the first reversing loading plate 1 and the second reversing loading plate 2, and are fixed by the straight connecting bolt 18, so that the eight roller connecting rods form a whole, so that the pressure is stable during the test and the confining pressure device is prevented from deforming or shifting.

[0057] In this embodiment, the confining pressure assembly further includes two overlapping curved connecting pieces 11 and two overlapping bolts 20. One end of the overlapping curved connecting piece 11 is fixed to the first reversing loading plate 1 by the overlapping bolts 20, and the other end of the overlapping curved connecting piece 11 is connected to the third roller connecting rod 5. The overlapping curved connecting piece 11 is used to prevent the confining pressure assembly from slipping during shear loading.

[0058] In this embodiment, the confining pressure assembly further includes two first pressure-bending connecting plates 7, two second pressure-bending connecting plates 8, two third pressure-bending connecting plates 9, and two fourth pressure-bending connecting plates 10. The two first pressure-bending connecting plates 7 are sequentially disposed at the lower ends of the first roller connecting rods 3, and the two first pressure-bending connecting plates 7 are simultaneously connected to the two first roller connecting rods 3. The two second pressure-bending connecting plates 8 are sequentially disposed at the lower ends of the second roller connecting rods 4, and the two second pressure-bending connecting plates 8 are simultaneously connected to the two second roller connecting rods 4. The two third pressure-bending connecting plates 9 are sequentially disposed at the upper ends of the third roller connecting rods 5, and the two third pressure-bending connecting plates 9 are simultaneously connected to the two third roller connecting rods 5. The two fourth pressure-bending connecting plates 10 are sequentially disposed at the upper ends of the fourth roller connecting rods 6, and the two fourth pressure-bending connecting plates 10 are simultaneously connected to the two fourth roller connecting rods 6. The multiple pressure-bending connecting plates stabilize the pressure during the test.

[0059] In this embodiment, the confining pressure assembly further includes curved connecting plate bolts 17 and roller connecting rod bolts 19. Two first pressure curved connecting plates 7 are fixed to each other by curved connecting plate bolts 17, two second pressure curved connecting plates 8 are fixed to each other by curved connecting plate bolts 17, two third pressure curved connecting plates 9 are fixed to each other by curved connecting plate bolts 17, and two fourth pressure curved connecting plates 10 are fixed to each other by curved connecting plate bolts 17. The curved connecting plate bolts 17 are used to prevent the confining pressure assembly from deforming or shifting.

[0060] Two first pressure-bending connecting plates 7 are sequentially fixed to the lower end of the first roller connecting rod 3 by roller connecting rod bolts 19. Two second pressure-bending connecting plates 8 are sequentially fixed to the lower end of the second roller connecting rod 4 by roller connecting rod bolts 19. Two third pressure-bending connecting plates 9 are sequentially fixed to the upper end of the third roller connecting rod 5 by roller connecting rod bolts 19. Two fourth pressure-bending connecting plates 10 are sequentially fixed to the upper end of the fourth roller connecting rod 6 by roller connecting rod bolts 19. The roller connecting rod bolts 19 fix different roller connecting rods and different pressure-bending connecting plates at two points to prevent deformation or misalignment of the confining pressure device.

[0061] In this embodiment, as Figures 2 to 4 As shown, the structure of the second reversing loading plate 2 is the same as that of the first reversing loading plate 1; as Figure 5 As shown, the structure of the second gasket 15 is the same as that of the first gasket 14; as Figures 6 to 8 As shown, the second roller connecting rod 4, the third roller connecting rod 5, and the fourth roller connecting rod 6 have the same structure as the first roller connecting rod 3; as Figure 9 As shown, the structures of the overlapping connecting piece 11, the second pressure-adjusting connecting piece 8, the third pressure-adjusting connecting piece 9, and the fourth pressure-adjusting connecting piece 10 are consistent with those of the first pressure-adjusting connecting piece 7; as Figure 10 As shown, the structure of the second straight connecting piece 13 is the same as that of the first straight connecting piece 12.

[0062] like Figure 11 As shown in the figure, this embodiment also provides a method for using a fixture for a compressive shear test of a micro seismic isolation bearing. The specific steps are as follows:

[0063] S1. First, the compression loading function of the electronic universal testing machine is used to compress and load the micro seismic isolation bearing specimen to be tested, the first reversing loading plate 1 and the second reversing loading plate 2 to the specified pressure, thereby providing pre-pressure to the micro seismic isolation bearing specimen to be tested.

[0064] S2. Then, under the pre-pressure described in step S1, the confining pressure assembly is installed, and the confining pressure assembly is overlapped with the first reversing loading plate 1 and the second reversing loading plate 2. At the same time, the micro-seismic isolation bearing specimen to be tested is fixed between the confining pressure assembly. Then, the micro-seismic isolation bearing specimen to be tested is unloaded from the first reversing loading plate 1 and the second reversing loading plate 2. Thus, during the unloading and rebound process of the micro-seismic isolation bearing specimen to be tested, the confining pressure assembly generates confining pressure, forming the pressure required for the pressure shear test.

[0065] S3. Then, using the tensile loading function of the electronic universal testing machine, the two ends of the first reversing loading plate 1 and the second reversing loading plate 2 are clamped at the upper chuck 21 or the lower chuck 22 of the electronic universal testing machine, and tensile loading is performed. At this time, the first reversing loading plate 1 and the second reversing loading plate 2 cooperate with the confining pressure structure to convert the axial tensile force generated by the electronic universal testing machine into the shear force required for the test of the micro-vibration isolation bearing specimen.

[0066] S4. During the loading process, the confining pressure assembly forms a symmetrical four-point confining pressure loading on the first reversing loading plate 1 and the second reversing loading plate 2 through the rollers. Since the rollers and the surfaces of the first reversing loading plate 1 and the second reversing loading plate 2 are lubricated, the confining pressure assembly can achieve stable confining pressure loading on the micro-isolation bearing specimen under almost no friction, thereby meeting the pressure shear test conditions.

[0067] S5. Finally, a unidirectional, cyclic compression shear test is conducted on the micro-isolation bearing specimen to be tested. The required mechanical parameters for shear stiffness and shear angle of the micro-isolation bearing specimen to be tested are calculated based on the slope of the force-displacement curve. The test is then completed.

[0068] In this embodiment, in step S3, the shear force (shear force) means: "shear" is the phenomenon of relative displacement deformation of the cross section of a material along the direction of the action of a pair of closely spaced, equal in magnitude and opposite in direction of the transverse external forces (i.e., forces perpendicular to the action surface); the force that can cause shear deformation of the material is called shear force or shear force, and the cross section in which shear deformation occurs is called the shear surface.

[0069] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method of using a fixture for a compressive shear test of a micro-seismic isolation bearing, wherein the fixture is mounted on an electronic universal testing machine for performing a compressive shear test on the micro-seismic isolation bearing, characterized in that... The fixture includes a reversing loading component and a confining pressure component; The reversing loading assembly includes a first reversing loading plate (1) and a second reversing loading plate (2). The first reversing loading plate (1) is used to connect with the upper chuck (21) of the testing machine, and the second reversing loading plate (2) is used to connect with the lower chuck (22) of the testing machine. The first reversing loading plate (1) and the second reversing loading plate (2) are arranged opposite to each other. The first reversing loading plate (1) and the second reversing loading plate (2) are parallel to the axial direction of the testing machine. The space between the first reversing loading plate (1) and the second reversing loading plate (2) is used to place the micro-vibration isolation bearing specimen to be tested. The confining pressure assembly includes a first roller connecting rod (3), a second roller connecting rod (4), a third roller connecting rod (5), and a fourth roller connecting rod (6). The first roller connecting rod (3) and the second roller connecting rod (4) are directly connected to the first reversing loading plate (1). The third roller connecting rod (5) and the fourth roller connecting rod (6) are directly connected to the second reversing loading plate (2). The first roller connecting rod (3) passing through the first reversing loading plate (1) is connected to the third roller connecting rod (5) passing through the second reversing loading plate (2). The second roller connecting rod (4) passing through the first reversing loading plate (1) is connected to the third roller connecting rod (5). The fourth roller connecting rod (6) passes through the second reversing loading plate (2) and is connected to the first roller connecting rod (3), the second roller connecting rod (4), the third roller connecting rod (5) and the fourth roller connecting rod (6) form a confining pressure structure; one end of the first roller connecting rod (3), the second roller connecting rod (4), the third roller connecting rod (5) and the fourth roller connecting rod (6) are all rollers, and the rollers are in direct contact with the first reversing loading plate (1) or the second reversing loading plate (2) as the application point of the confining pressure. Four-point pressure is applied on the first reversing loading plate (1) or the second reversing loading plate (2) through the rollers; The first reversing loading plate (1) and the second reversing loading plate (2) cooperate with the confining pressure structure to convert the axial tensile force of the electronic universal testing machine into shear force, thereby performing a pressure shear test on the micro-isolation bearing specimen to be tested; The method of use specifically includes the following steps: S1. Using the compression loading function of the electronic universal testing machine, the micro-isolation bearing specimen to be tested, the first reversing loading plate (1) and the second reversing loading plate (2) are compressed and loaded to a specified pressure, thereby providing pre-pressure to the micro-isolation bearing specimen to be tested. S2. Install the confining pressure assembly under the pre-pressure described in step S1, and overlap the confining pressure assembly with the first reversing loading plate (1) and the second reversing loading plate (2). At the same time, fix the micro-seismic isolation bearing specimen to be tested between the confining pressure assembly, and then unload the micro-seismic isolation bearing specimen to be tested from the first reversing loading plate (1) and the second reversing loading plate (2). Thus, during the unloading and rebound process of the micro-seismic isolation bearing specimen to be tested, the confining pressure assembly generates confining pressure, forming the pressure required for the pressure shear test. S3. Using the tensile loading function of the electronic universal testing machine, clamp the two ends of the first reversing loading plate (1) and the second reversing loading plate (2) at the upper chuck (21) or lower chuck (22) of the electronic universal testing machine and perform tensile loading. At this time, the first reversing loading plate (1) and the second reversing loading plate (2) cooperate with the confining pressure structure to convert the axial tensile force generated by the electronic universal testing machine into the shear force required for the test of the micro-isolation bearing specimen. S4. During the loading process, the confining pressure assembly forms a symmetrical four-point confining pressure loading on the first reversing loading plate (1) and the second reversing loading plate (2) through rollers; S5. Finally, a unidirectional, cyclic compression shear test is conducted on the micro-isolation bearing specimen to be tested. The required mechanical parameters for shear stiffness and shear angle of the micro-isolation bearing specimen to be tested are calculated based on the slope of the force-displacement curve. The test is then completed.

2. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 1, characterized in that, The reversing loading assembly also includes a specimen bolt (16), a first shim (14), and a second shim (15). The first shim (14) is fixed to the first reversing loading plate (1) by four specimen bolts (16), and the second shim (15) is fixed to the second reversing loading plate (2) by four specimen bolts (16). The first shim (14) and the second shim (15) are used to fix the micro-seismic isolation bearing specimen to be tested between the first reversing loading plate (1) and the second reversing loading plate (2). The specimen bolt (16) is used to fix the first shim (14) or the second shim (15) to provide stable shear loading conditions. The gap between the first reversing loading plate (1) and the second reversing loading plate (2) is adjusted by the first shim (14) and the second shim (15) of different thicknesses.

3. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 1, characterized in that, The first reversing loading plate (1) and the second reversing loading plate (2) are steel plates.

4. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 2, characterized in that, The first reversing loading plate (1) and the second reversing loading plate (2) are provided with bolt holes. The test bolt (16) passes through the bolt hole and connects with the first washer (14) or the second washer (15). The test bolt (16) is used to fix the micro seismic isolation bearing test specimen to be tested between the first reversing loading plate (1) and the second reversing loading plate (2).

5. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 1, characterized in that, The confining pressure assembly includes two first roller connecting rods (3), two second roller connecting rods (4), two third roller connecting rods (5) and two fourth roller connecting rods (6). The two first roller connecting rods (3) and the two second roller connecting rods (4) are respectively located on both sides of the first reversing loading plate (1), and the two third roller connecting rods (5) and the two fourth roller connecting rods (6) are respectively located on both sides of the second reversing loading plate (2).

6. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 5, characterized in that, The confining pressure assembly also includes a straight connecting plate bolt (18), two first straight connecting plates (12) and two second straight connecting plates (13). The first roller connecting rod (3), the first straight connecting plate (12), the second straight connecting plate (13) and the third roller connecting rod (5) are connected in sequence and fixed by the straight connecting plate bolt (18). The second roller connecting rod (4), the first straight connecting plate (12), the second straight connecting plate (13) and the fourth roller connecting rod (6) are connected in sequence and fixed by the straight connecting plate bolt (18). The first straight connecting plate (12) and the second straight connecting plate (13) are used to connect the roller connecting rods on the same side of the first reversing loading plate (1) and the second reversing loading plate (2) and are fixed by the straight connecting plate bolt (18).

7. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 5, characterized in that, The confining pressure assembly also includes two overlapping curved connecting pieces (11) and two overlapping bolts (20). One end of the overlapping curved connecting piece (11) is fixed to the first reversing loading plate (1) by the overlapping bolts (20), and the other end of the overlapping curved connecting piece (11) is connected to the third roller connecting rod (5). The overlapping curved connecting piece (11) is used to prevent the confining pressure assembly from slipping during shear loading.

8. The method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 5, characterized in that, The confining pressure assembly further includes two first pressure-bending connecting plates (7), two second pressure-bending connecting plates (8), two third pressure-bending connecting plates (9), and two fourth pressure-bending connecting plates (10). The two first pressure-bending connecting plates (7) are sequentially disposed at the lower end of the first roller connecting rod (3), and the two first pressure-bending connecting plates (7) are simultaneously connected to the two first roller connecting rods (3). The two second pressure-bending connecting plates (8) are sequentially disposed at the lower end of the second roller connecting rod (4), and the two second pressure-bending connecting plates (8) are simultaneously connected to the two second roller connecting rods (4). The two third pressure-bending connecting plates (9) are sequentially disposed at the upper end of the third roller connecting rod (5), and the two third pressure-bending connecting plates (9) are simultaneously connected to the two third roller connecting rods (5). The two fourth pressure-bending connecting plates (10) are sequentially disposed at the upper end of the fourth roller connecting rod (6), and the two fourth pressure-bending connecting plates (10) are simultaneously connected to the two fourth roller connecting rods (6).

9. A method of using a fixture for a compressive shear test of a micro-isolation bearing according to claim 8, characterized in that, The confining pressure assembly also includes curved connecting plate bolts (17) and roller connecting rod bolts (19). Two first pressure curved connecting plates (7) are fixed to each other by curved connecting plate bolts (17), two second pressure curved connecting plates (8) are fixed to each other by curved connecting plate bolts (17), two third pressure curved connecting plates (9) are fixed to each other by curved connecting plate bolts (17), and two fourth pressure curved connecting plates (10) are fixed to each other by curved connecting plate bolts (17). Two first pressure-bending connecting pieces (7) are sequentially fixed to the lower end of the first roller connecting rod (3) by roller connecting rod bolts (19), two second pressure-bending connecting pieces (8) are sequentially fixed to the lower end of the second roller connecting rod (4) by roller connecting rod bolts (19), two third pressure-bending connecting pieces (9) are sequentially fixed to the upper end of the third roller connecting rod (5) by roller connecting rod bolts (19), and two fourth pressure-bending connecting pieces (10) are sequentially fixed to the upper end of the fourth roller connecting rod (6) by roller connecting rod bolts (19).

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