Assembled axis and eccentricity reciprocating tension-compression test device suitable for structural member and test method of assembled axis and eccentricity reciprocating tension-compression test device

Abstract

The invention provides an assembly type axis and eccentricity reciprocating tension-compression test device and test method suitable for structural members, and belongs to the technical field of building structures. The problem that an existing test device can only achieve monotonous compression or monotonous tension working conditions and cannot achieve reciprocating tension-compression test loading is solved. The device mainly comprises a loading equipment connecting part, a test component connecting part and a test component. The problems that the end of a structural member is prone to being damaged in advance during reciprocating pulling-pressing loading, pulling-pressing load transmission is insufficient and the like are effectively solved, effective transmission and conversion of the pulling-pressing load in the metal pipe-concrete combined member are guaranteed, and the position of the pulling-pressing rotating shaft is adjusted through the eccentricity rate adjusting shaft. According to the invention, the tension-compression reciprocating load with any eccentricity can be applied to the structural member, the assembly type mechanical connection is adopted, the assembly operation of the test device is convenient, the rapid installation and rapid replacement of the test member and the loading device can be realized, and the extra workload in the test process is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of building structures, and in particular relates to an assembled axial and eccentric reciprocating tension-compression test device and a test method suitable for structural components. Background Art

[0002] Metal tube components and metal tube-concrete composite components are two types of building structural components that are currently widely used. Metal tubes are mainly common structural steel tubes, stainless steel tubes and other weldable metal tubes. The internal filling concrete of metal tube-concrete composite structural components includes ordinary concrete, high-strength concrete, recycled concrete, ultra-high performance concrete, etc. The above-mentioned structural components have been widely used in industrial plants, stadiums, high-rise buildings, large-span bridges, transmission towers and other structures. When encountering earthquake loads or wind loads, metal tubes or metal tube-concrete composite components are often in a reciprocating tension-compression stress state. The reciprocating tension-compression damage of structural components is the key reason for their performance degradation or even failure, and it is also the basis for analyzing their failure mechanism under the reciprocating action of multiple load coupling.

[0003] However, existing test devices can often only realize monotonic compression or monotonic tension tests on metal tubes or metal tube-concrete composite components. When conducting tension-compression tests, the failure area of ​​some existing tension-compression test devices often appears at the connection joints at the ends of the specimens, and the heat-affected zone of the end welding often fails before the specimen. When the specimen is a metal tube-concrete composite component, the existing device cannot fully ensure that the tension-compression load is effectively transmitted to the core concrete inside, resulting in the metal tube being directly stressed and not forming a combined effect with the core concrete. In addition, the existing device is prone to stress concentration when only relying on bolts for tension, and the end plate is prone to bending deformation during tension-compression conversion, resulting in excessive virtual displacement of the specimen, distorted test results, and unable to realize the study of the reciprocating tension-compression mechanical properties of metal tube components and metal tube-concrete composite components.

[0004] In addition, when the specimen is under eccentric stress, the eccentricity of the existing loading device is difficult to adjust or the adjustable accuracy is insufficient, and the welding area and bolt connection area at the end of the metal pipe are more prone to brittle failure under the reciprocating tension-bending coupled load. The hinged boundary conditions at the end of the specimen make it difficult to ensure that the specimen can rotate freely under the action of bending moment, resulting in the test results being unable to reflect the actual stress conditions of the specimen. Summary of the invention

[0005] In view of this, the present invention aims to solve the problem that the existing test devices can only realize monotonic compression or monotonic tension conditions and cannot perform reciprocating tension-compression tests; and the existing tension-compression test devices often suffer brittle failure at the end connections, and the end clamps and bolt tensions are difficult to ensure the effective transmission and smooth conversion of tension-compression loads in the metal tube-concrete composite structure; when there is an eccentric load, the existing loading device is also unable to realize the application of arbitrary eccentric loads, and the rotation ability of the end cannot be fully guaranteed, and virtual displacement will be generated during the loading process, resulting in insufficient reliability of the reciprocating tension-compression test results of the metal tube or metal tube-concrete composite component.

[0006] In order to solve the above problems, the present invention adopts the following technical solutions: an assembled axial and eccentric reciprocating tension-compression test device and test method suitable for structural members, comprising a loading device connecting part, a test member connecting part and a test member, wherein the loading device connecting part is connected to the test member connecting part, and the test member connecting part is connected to the test member;

[0007] The loading device connection part includes a chuck end, a chuck plate and a chuck cover plate, the chuck plate is located below the chuck end, and the chuck cover plate fixes the chuck end and the chuck plate;

[0008] The connecting part of the test component includes a connecting plate, an eccentricity adjustment shaft, a tension-compression shaft and a connecting base plate. The connecting base plate is vertically mounted with a connecting plate, the connecting plate is provided with an axial loading fixing hole II, the connecting plate is provided with a slide groove, the tension-compression shaft is installed in the slide groove, and the eccentricity adjustment shaft crosses the slide groove and passes through the tension-compression shaft at the same time. The tension-compression shaft is a cubic steel block with round steel columns welded at both ends, and the middle part is drilled for wire cutting, and the wire cutting parameters are consistent with the eccentricity adjustment shaft.

[0009] Furthermore, an axial loading fixing hole I is provided on the chuck end, and an axial loading fixing hole II is provided on the connecting plate of the connecting part of the test component. When axial loading is required, pins can be inserted into the axial loading fixing hole I and the axial loading fixing hole II to ensure that the load is applied axially.

[0010] Furthermore, the tension-compression load is applied by an MTS testing machine, which is equipped with a fixture, and the chuck end 1-1 is inserted into the fixture and clamped, and the load is applied by using the friction force between the fixture and the chuck end.

[0011] Furthermore, the connection parts of the loading device and the connection parts of the test component need to be assembled before the test. During assembly, the tension-compression shaft is placed in the corresponding slide groove position of the connecting plate, and then the eccentricity adjustment shaft is inserted. After adjusting and determining the required eccentricity, the nut on the outside of the eccentricity adjustment shaft is tightened, and the position of the tension-compression shaft is fixed.

[0012] Furthermore, the test component connection part also includes a center bolt, the connecting base plate is connected to the test component through the center bolt, the center bolt includes a straight screw, a nut and a plurality of shear keys, a nut is installed at one end of the center bolt, and a plurality of shear keys are welded on the periphery of the center bolt.

[0013] Furthermore, the test component part includes two end plates, an outer metal tube and core concrete. The upper and lower ends of the outer metal tube are respectively connected to the end plates. The center of the end plate is drilled and wire-cut. The outer metal tube is filled with core concrete.

[0014] Furthermore, the end plate is provided with an arcuate groove, the edge of the groove is processed with a groove, an arcuate portion is cut out at a corresponding position of the end of the outer metal tube, and the outer metal tube is inserted into the end plate and connected by plug welding.

[0015] Furthermore, the test component part needs to be processed and assembled before the experiment. The center bolt can be unscrewed from the side of the component to the outside, and the upper part of the straight screw passes through the center hole of the end plate and is unscrewed to the corresponding length according to the design. Then, one side of the end plate is plug-welded to the outer metal tube. When there is core concrete in the tube, concrete is poured, and the other side end plate is installed before the concrete solidifies. Similarly, the straight screw needs to be screwed in in advance, and plug welding is performed after the core concrete is cured. When the component is only a metal tube, the shear key may not be welded to the lower part of the straight screw, and the end plates on both sides can be plug-welded to the outer metal tube at the same time. After the end plates on both sides are plug-welded to the outer metal tube, the metal tube stiffening ribs can be welded, and the welding position is the unplug-welded part of the outer metal tube.

[0016] Furthermore, after the test component is partially processed and assembled, the upper part of the straight screw extending out of the end plate is passed through the center hole of the connecting base plate and then fastened to the connecting base plate using the corresponding nut. Subsequently, the U-shaped pad is embedded and the limit bolt is screwed in to prevent the U-shaped pad from slipping out during loading. The corner bolts are respectively passed through the corner bolt holes of the connecting base plate and the component end plate and tightened to complete the assembly of the entire device.

[0017] A test method using the assembled axial and eccentric reciprocating tension-compression test device suitable for structural members comprises the following steps:

[0018] S1. Assembly process: Design the corresponding components according to the test requirements, connect the end plate of the test component with the connecting bottom plate using the center bolts and corner bolts, then complete the connection between the connecting part of the loading device and the connecting part of the test component, insert the chuck end into the MTS fixture and clamp it, complete the connection between the test device and the loading device, and install the strain monitoring equipment and displacement monitoring equipment according to the test requirements;

[0019] S2. Test process: Use the MTS load application device to apply axial or eccentric loads to the test component. The load is any one or a combination of monotonic tension load, monotonic compression load, cyclic tension load, cyclic compression load or cyclic tension-compression load.

[0020] Compared with the prior art, the assembled axial and eccentric reciprocating tension-compression test device and test method for structural components described in the present invention have the following beneficial effects:

[0021] 1. The present invention realizes the application of tensile-compressive reciprocating loads to structural components and the end connections are reliable, while reducing the generation of virtual displacement when the load is applied, further improving the test operability and test accuracy. The designed test component connection part connects the loading device and the test component, which can effectively transmit the tensile-compressive load applied by the loading device, and realize the tensile-compressive reciprocating loading of the structural component; the outer metal pipe is cut according to the design and inserted into the arc groove groove of the end plate for plug welding, and stiffening ribs are used at the same time to ensure the reliable connection between the test piece and the end plate, avoiding the problem of brittle failure of traditional fillet welds in the heat affected zone of the end welding; the lower part of the center bolt is connected to the end plate of the test component by threaded connection, and the upper part of the center bolt is tightened with bolts to effectively avoid the problem of the center of the connecting bottom plate and the end plate of the test component being empty when the tensile-compressive load is applied.

[0022] 2. The present invention realizes the effective transfer of tension-compression loads in metal tube-concrete composite structural components. The central bolt and the four corner bolts work together to make the connecting base plate and the end plate of the test component fit tightly. Under the compressive load, the end plate of the test component transmits uniform pressure. At this time, the outer metal tube and the core concrete share the load. Under the tensile load, the end plate of the test component directly transfers the tensile force to the outer metal tube. The lower part of the central bolt embedded in the core concrete is welded with a shear key, which transfers the tensile force to the core concrete, so that the outer metal tube and the core concrete share the tensile force, ensuring the effective transfer of tension-compression loads. Appropriately describe the effect of tension-compression conversion.

[0023] 3. The present invention can ensure the rotation ability of the end of the test component and realize the application of any eccentric load. The position of the tension-compression rotation axis is adjusted by the eccentricity adjustment axis, and a tension-compression load with any eccentricity is applied to the test component. In addition, the connection part of the loading device and the connection part of the test component can be locally designed according to the research requirements and the size of the test component to meet the special eccentricity requirements.

[0024] 4. The present invention adopts assembled mechanical connection, and the test device assembly operation is convenient, and the test components can be quickly installed. If the device components are damaged, they can be quickly replaced, which improves the utilization rate of structural materials and reduces the extra workload during the test. In addition, the present invention has a wide range of applications and can be used to study the reciprocating tension-compression performance of metal pipe components and metal pipe-concrete composite components. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of an assembled axial and eccentric reciprocating tension-compression test device suitable for structural components in an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a connection portion of a loading device in an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of a connection portion of a test component in an embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of an eccentricity adjustment part in an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of a U-shaped pad in an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of the connection of a metal tube-concrete composite component in an embodiment of the present invention;

[0032] Figure 7 A schematic diagram of the connection of metal pipe components in an embodiment of the present invention;

[0033] Figure 8 is a schematic diagram of a central bolt in an embodiment of the present invention;

[0034] Description of reference numerals:

[0035] Loading device connection part 1, chuck end 1-1, chuck plate 1-2, chuck cover plate 1-3, chuck bolt 1-4, axial loading fixing hole Ⅰ 1-5;

[0036] Test component connection part 2, connection plate 2-1, eccentricity adjustment shaft 2-2, tension-compression shaft 2-3, axial loading fixing hole II 2-4, stiffening rib 2-5, connection base plate 2-6, center bolt 2-7, corner bolt 2-8, straight screw 2-71, nut 2-72, shear key 2-73, U-shaped pad 2-9, limit bolt 2-91;

[0037] Test component part 3, end plate 3-1, outer metal tube 3-2, core concrete 3-3, metal tube stiffening rib 3-4. Specific implementation methods

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0039] See also Figure 1-8 The present implementation method is described as an assembled axial and eccentric reciprocating tension-compression test device suitable for structural members, comprising a loading device connection part 1, a test member connection part 2 and a test member 3, wherein the loading device connection part 1, the test member connection part 2 and the test member 3 are connected in sequence.

[0040] Combination Figure 2 As shown, the loading device connection part 1 includes a chuck end 1-1, a chuck plate 1-2, a chuck cover plate 1-3, a chuck bolt 1-4, and an axial loading fixing hole Ⅰ1-5. The above components can be completed by cutting and welding steel plates. The chuck end 1-1 includes a cubic part and a U-shaped part. The axial loading fixing hole Ⅰ1-5 on the chuck end 1-1 is drilled, and the corresponding positions of the four chuck bolts 1-4 are drilled and wired. The corresponding positions of the four chuck bolts 1-4 on the chuck plate 1-2 are drilled and wired, and the corresponding positions of the four chuck bolts 1-4 on the chuck cover plate 1-3 are drilled. The tension-compression load is applied by the MTS (electro-hydraulic servo loading test system) testing machine. The MTS testing machine is equipped with a fixture. The upper cubic part of the chuck end 1-1 is inserted into the fixture and clamped, and the load is applied by the friction between the fixture and the chuck end.

[0041] Combination Figures 3 to 5 As shown, the test component connection part 2 includes a connection plate 2-1, an eccentricity adjustment shaft 2-2, a tension-compression shaft 2-3, an axial loading fixing hole II 2-4, a stiffening rib 2-5, a connection base plate 2-6, a center bolt 2-7, a corner bolt 2-8, a U-shaped pad 2-9, and a limit bolt 2-91. The connection plate 2-1, the stiffening rib 2-5, and the connection base plate 2-6 can be completed by cutting and welding steel plates, and holes are drilled at corresponding positions. The eccentricity adjustment shaft 2-2 is a long rod bolt, and the tension-compression shaft 2-3 is a cubic steel block with round steel columns welded at both ends. The center hole is drilled for wire cutting, and the wire cutting parameters are consistent with the eccentricity adjustment shaft 2-2. The eccentricity adjustment shaft 2-2 can be screwed in and passed through the tension-compression shaft 2-3. The U-shaped pad 2-9 is machined from a cubic steel block, has the same height as the rectangular space reserved at the bottom of the connecting plate 2-1, is slightly narrower in width, has holes drilled at corresponding positions on the side, and can be screwed into the limit bolts 2-91.

[0042] The connecting base plate 2-6 is connected to the test member 3 through a central bolt 2-7 and a corner bolt 2-8. The central bolt 2-7 includes a straight screw rod 2-71, a nut 2-72 and a plurality of shear keys 2-73. A nut 2-72 is installed at one end of the central bolt 2-7, and a plurality of shear keys 2-73 are welded to the periphery of the central bolt 2-7.

[0043] Combination Figures 1 to 5 As shown, the loading device connection part 1 and the test component connection part 2 need to be assembled before the test. During assembly, the tension-compression shaft 2-3 is placed in the corresponding slide groove position of the connecting plate 2-1, and then the eccentricity adjustment shaft 2-2 is inserted. After adjusting and determining the required eccentricity, the nut on the other side of the eccentricity adjustment shaft 2-2 is tightened, and the position of the tension-compression shaft 2-3 is fixed. The U-shaped part of the chuck end 1-1 is inserted into the connecting plate 2-1, and the semicircular groove of the U-shaped part of the chuck end 1-1 and the semicircular groove of the chuck plate 1-2 surround the two side cylinders of the tension-compression shaft 2-3. The chuck cover plate 1-3 and the chuck bolt 1-4 are used to connect the chuck end 1-1 and the chuck plate 1-2.

[0044] Combination Figures 6 to 8 As shown, the test component part 3 includes an end plate 3-1, an outer metal tube 3-2 and a core concrete 3-3. The upper and lower ends of the outer metal tube 3-2 are respectively connected to the end plate 3-1, the center of the end plate 3-1 is drilled and wired, and the core concrete 3-3 is filled in the outer metal tube 3-2. An arc groove is opened in the end plate 3-1, and a groove is processed at the edge of the groove. An arc portion is cut at the corresponding position of the end of the outer metal tube 3-2, and the outer metal tube 3-2 is inserted into the end plate 3-1 and connected by plug welding.

[0045] Combination Figure 6 , Figure 7 As shown, the test component part 3 needs to be processed and assembled before the experiment. The center bolt 2-7 can be screwed out from the side of the component to the outside, and the upper part of the straight screw 2-71 passes through the center hole of the end plate 3-1, and is screwed out to the corresponding length according to the design, and then the end plate 3-1 on one side is plug-welded to the outer metal tube 3-2. When there is core concrete 3-3 in the tube, concrete is poured, and the other end plate 3-1 is installed before the concrete solidifies. Similarly, the straight screw 2-71 needs to be screwed in in advance, and plug welding is performed after the core concrete 3-3 is cured; when the component is only a metal tube, the shear key 2-73 may not be welded at the lower part of the straight screw 2-71, and the length of the straight screw 2-71 may be reduced accordingly, and the end plates 3-1 on both sides and the outer metal tube 3-2 can be plug-welded at the same time. After the end plates 3-1 on both sides and the outer metal tube 3-2 are plug-welded, the metal tube stiffening ribs 3-4 can be welded, and the welding position is the part of the outer metal tube 3-2 that has not been plug-welded.

[0046] Combination Figures 1 to 8As shown, after the test component part 3 is processed and assembled, the upper part of the straight screw 2-71 extending out of the end plate 3-1 passes through the center hole of the connecting bottom plate 2-6 and is connected and fastened with the connecting bottom plate 2-6 using the corresponding nut 2-73, and then is embedded in the U-shaped pad 2-9 and screwed into the limit bolt 2-91 to prevent the U-shaped pad from slipping out during loading. The corner bolts 2-8 pass through the corner bolt holes of the connecting bottom plate 2-6 and the component end plate 3-1 respectively and are tightened to complete the assembly of the entire device.

[0047] Furthermore, the components in the test device are all connected by cutting and welding of steel plates, and the loading device connection part 1 and the test component connection part 2 are recommended to use metal materials with higher strength and stiffness than the test component part 3.

[0048] Furthermore, the cubic part of the chuck end 1-1 can have different cross-sectional shapes such as circular, square, and diamond according to the loading device fixture.

[0049] Furthermore, the size of the test component connection portion 2 can be designed according to test requirements to achieve large eccentricity loading.

[0050] Furthermore, the outer metal tube 3-2 can be a steel tube of different materials, a stainless steel tube, etc., and the core concrete 3-3 can be different types of ordinary concrete, high-strength concrete, recycled concrete, self-compacting concrete, etc.

[0051] Furthermore, when axial loading is required, pins can be inserted into the axial loading fixing holes Ⅰ1-5 and the axial loading fixing holes Ⅱ2-4 to ensure that the load is applied in the axial direction.

[0052] Furthermore, it is recommended that bolts and screws be made of high-strength materials to ensure the connection strength of the loading device.

[0053] Furthermore, the U-shaped pad 2-9 fits tightly with the connecting plate 2-1 and the center bolt 2-7 to ensure the transmission of axial force and improve the rigidity of the device.

[0054] Combination Figures 1 to 6 As shown, the present invention provides an assembled reciprocating tension-compression test method suitable for structural members, comprising the following steps:

[0055] S1. Assembly process: Design corresponding components according to test requirements, connect the test component end plate 3-1 and the connecting bottom plate 2-6 with the center bolt 2-7 and the corner bolt 2-8. Then complete the connection between the loading device connection part 1 and the test component connection part 2. Insert the chuck end 1-1 into the MTS fixture and clamp it to complete the connection between the test device and the loading device. Install strain monitoring equipment and displacement monitoring equipment according to test requirements.

[0056] S2. During the test, the MTS load application device is used to apply axial or eccentric loads to the test component. The load can be any one or a combination of monotonic tension load, monotonic compression load, cyclic tension load, cyclic compression load or cyclic tension-compression load. The magnitude of the axial force applied by the load, the deformation of the test component, etc. can be collected by the corresponding device.

[0057] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. An assembled axial and eccentric reciprocating tension-compression test method suitable for structural components, characterized in that: The following steps are involved: S1. Assembly process: Design the corresponding components according to the test requirements, connect the end plate (3-1) of the test component to the connecting base plate (2-6) using the center bolt (2-7) and the corner bolt (2-8), then connect the loading device connection part (1) to the test component connection part (2), insert the chuck end (1-1) into the MTS fixture and clamp it, complete the connection between the test device and the loading device, and install the strain monitoring device and the displacement monitoring device according to the test requirements; S2. Test process: An axial or eccentric load is applied to the test component (3) using an MTS load application device. The load is any one or a combination of monotonic tension load, monotonic compression load, cyclic tension load, cyclic compression load or cyclic tension-compression load.

2. A device for use in the assembled axial and eccentric reciprocating tension-compression test method for structural members as claimed in claim 1, characterized in that: The device comprises a loading device connection part (1) and a test member connection part (2), wherein the loading device connection part (1) and the test member connection part (2) are connected, and the test member connection part (2) is connected to the test member (3); The loading device connection part (1) comprises a chuck end (1-1), a chuck plate (1-2) and a chuck cover plate (1-3), wherein the chuck plate (1-2) is disposed below the chuck end (1-1), and the chuck cover plate (1-3) fixedly connects the chuck end (1-1) and the chuck plate (1-2). The test component connection part (2) comprises a connection plate (2-1), an eccentricity adjustment shaft (2-2), a tension-compression shaft (2-3) and a connection base plate (2-6); the connection plate (2-1) is vertically mounted on the connection base plate (2-6); the connection plate (2-1) is provided with an axial loading fixing hole II (2-4); the connection plate (2-1) is provided with a slide groove, the tension-compression shaft (2-3) is mounted in the slide groove, and the eccentricity adjustment shaft (2-2) crosses the slide groove and passes through the tension-compression shaft (2-3) at the same time.

3. The assembled axial and eccentric reciprocating tension-compression test device for structural members according to claim 2, characterized in that: An axial loading fixing hole I (1-5) is provided on the chuck end (1-1), and an axial loading fixing hole II (2-4) is provided on the connecting plate (2-1) of the connecting part (2) of the test component. When axial loading is required, pins can be inserted into the axial loading fixing hole I (1-5) and the axial loading fixing hole II (2-4) to ensure that the load is applied in the axial direction.

4. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 2, characterized in that: The tension-compression load is applied by an MTS testing machine equipped with a clamp. The chuck end (1-1) is inserted into the clamp and clamped, and the load is applied by the friction between the clamp and the chuck end.

5. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 2, characterized in that: The loading device connection part (1) and the test component connection part (2) need to be assembled before the test. During the assembly, the tension-compression shaft (2-3) is placed in the corresponding slide groove position of the connection plate (2-1), and then the eccentricity adjustment shaft (2-2) is inserted. After the required eccentricity is adjusted and determined, the nut on the outside of the eccentricity adjustment shaft (2-2) is tightened, and the position of the tension-compression shaft (2-3) is fixed.

6. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 2, characterized in that: The test component connection part (2) also includes a central bolt (2-7), and the connection base plate (2-6) is connected to the test component (3) via the central bolt (2-7). The central bolt (2-7) includes a straight screw (2-71), a nut (2-72) and a plurality of shear keys (2-73). A nut (2-72) is installed at one end of the central bolt (2-7), and a plurality of shear keys (2-73) are welded to the periphery of the central bolt (2-7).

7. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 6, characterized in that: The test component part (3) comprises two end plates (3-1), an outer metal tube (3-2) and core concrete (3-3); the upper and lower ends of the outer metal tube (3-2) are respectively connected to the end plates (3-1); a hole is drilled in the center of the end plate (3-1) for wire cutting; and the core concrete (3-3) is filled in the outer metal tube (3-2).

8. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 7, characterized in that: The end plate (3-1) is provided with an arc-shaped groove, the edge of the groove is processed with a groove, an arc-shaped portion is cut out at a corresponding position of the end of the outer metal tube (3-2), and the outer metal tube (3-2) is inserted into the end plate (3-1) and connected by plug welding.

9. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 8, characterized in that: The test component part (3) needs to be processed and assembled before the experiment. The center bolt (2-7) can be screwed out from the side of the component to the outside. The upper part of the straight screw (2-71) passes through the center hole of the end plate (3-1) and is screwed out to the corresponding length according to the design. Then, one side of the end plate (3-1) is plug-welded to the outer metal pipe (3-2). When there is core concrete (3-3) in the pipe, concrete is poured. Before the concrete solidifies, the other side of the end plate (3-1) is installed. Similarly, the straight screw (2-71) needs to be screwed in in advance, and plug welding is performed after the core concrete (3-3) is cured; when the component is only a metal tube, the shear key (2-73) may not be welded to the lower part of the straight screw (2-71), and the end plates (3-1) on both sides and the outer metal tube (3-2) can be plug welded at the same time. After the end plates (3-1) on both sides and the outer metal tube (3-2) are plug welded, the metal tube stiffening rib 3-4 can be welded, and the welding position is the unplug-welded part of the outer metal tube (3-2).

10. The assembled axial and eccentric reciprocating tension-compression testing device for structural members according to claim 9, characterized in that: After the processing and assembly of the test component part (3) is completed, the upper part of the straight screw (2-71) extending out of the end plate (3-1) passes through the center hole of the connecting base plate (2-6) and is connected and fastened with the connecting base plate (2-6) using the corresponding nut (2-72), and then the U-shaped pad (2-9) is embedded and the limit bolt (2-91) is screwed in to prevent the U-shaped pad (2-9) from slipping out during loading. The corner bolts (2-8) are respectively passed through the corner bolt holes of the connecting base plate (2-6) and the component end plate (3-1) and tightened to complete the assembly of the entire device.

Images