A loading device suitable for low-cycle reciprocating pure torsion test

Abstract

The present invention relates to the field of structural test loading technology, specifically a loading device suitable for low-cycle reciprocating pure torsion test. In order to solve the problem that the prior art cannot realize the application of pure torque to the structure, a new loading device suitable for low-cycle reciprocating pure torsion test is provided, including an XY slide rail system, two reaction walls, and two pulling systems. The XY slide rail system includes a first-layer track group, a second-layer track group, and a third-layer track group. The XY slide rail system is located between the two reaction walls. The second-layer track group is slidably connected to the first-layer track group along the X-axis direction, and the third-layer track group is slidably connected to the second-layer track group along the Y-axis direction. One end of the two pulling systems is respectively hinged to the two reaction walls, and the other ends of the two pulling systems are respectively hinged to the two ends of the three-layer track group in the Y-axis direction. The two pulling systems are arranged in parallel and the angle between each pulling system and the three-layer track group is an acute angle. The present invention can realize the low-cycle reciprocating pure torsion test of the structure.

Description

Technical Field

[0001] The invention relates to the technical field of structural test loading, in particular to a loading device suitable for low-cycle reciprocating pure torsion test. Background Art

[0002] The low-cycle reciprocating pure torsion test is also called a quasi-static test. It is a test that uses a loading device to apply a gradually increasing and decreasing reciprocating load or reciprocating displacement to the structure. It is a test method for structural seismic research. The loading device of the low-cycle reciprocating pure torsion test is different depending on the object being tested. The object being tested can be a component or a structure. The center of rigidity and center of mass of a component generally coincide, so it is relatively easy to implement a pure torsion test. There are many loading devices suitable for low-cycle reciprocating pure torsion tests on components in the prior art, but the center of rigidity and center of mass of the structure generally do not coincide under actual working conditions, that is, the structure undergoes a translational torsion coupling when it is torsionally deformed. Therefore, the conventional loading device loaded on the structure will also undergo translational torsion coupling with the structure, making it difficult to separate the translational and torsion external force inputs, resulting in the inability to apply pure torque to the structure, thereby affecting the study of the torsion performance of the structure. Summary of the invention

[0003] In order to solve the problem that the prior art cannot realize the application of pure torque to the structure, the present invention provides a new loading device suitable for low-cycle reciprocating pure torque test.

[0004] The present invention is achieved by adopting the following technical solutions:

[0005] A loading device suitable for a low-cycle reciprocating pure torsion test comprises an XY slide rail system, two reaction walls arranged side by side along an X-axis direction, and two pulling systems with a force measuring function. The XY slide rail system comprises a first-layer track group, a second-layer track group, and a third-layer track group. The XY slide rail system is located between the two reaction walls. The first-layer track group is arranged along the X-axis direction, the second-layer track group is slidably connected to the first-layer track group along the X-axis direction, and the third-layer track group is slidably connected to the second-layer track group along the Y-axis direction. One end of the two pulling systems is respectively hinged to the two reaction walls, and the other ends of the two pulling systems are respectively hinged to the two ends of the three-layer track group in the Y-axis direction. The two pulling systems are arranged in parallel, and the angle between each pulling system and the three-layer track group is an acute angle.

[0006] Principle description: The loading device utilizes the sliding characteristics of the XY slide rail system to release the translational freedom of the loading device in the XY direction of the horizontal plane, so that the loading device can separate the translational and torsional external force inputs when torque loading is performed on the structure, and release the translational external force through the XY slide rail system, so that when the loading device follows the translational and torsional coupling deformation of the structure, no other external force inputs such as translational external force are generated except torque, thereby realizing a low-cycle reciprocating pure torsion test of the structure.

[0007] During installation, the loading device is fixed to the structure by fixing a track group of the loading device to the top surface of the structure (how to fix a track group of the loading device to the top surface of the structure is common knowledge for those skilled in the art, and can be achieved by bonding or bolting). At the same time, torsion sensors are installed on the traction systems on both sides and the structure. During the test, the layers of the XY slide rail system are connected by sliding in the X-axis and Y-axis directions, and the Z-axis rotational freedom is constrained. After the pure torque is input to the three-layer track group through the traction system, the pure torque will be transmitted downward to the structure layer by layer. If relative sliding occurs between the track groups of each layer, it indicates that the rigid center and the center of mass of the structure do not coincide, and the structure to be tested exhibits a flat torsion coupling deformation under pure torque; if relative sliding does not occur between the track groups of each layer, it indicates that the rigid center and the center of mass of the structure to be tested coincide, and the structure only undergoes torsional deformation. Therefore, when calculating the input pure torque, only the top three-layer track group and the traction system need to be considered.

[0008] Furthermore, the first-layer track group includes two first guide rails whose length directions are arranged along the X-axis direction and distributed side by side, the second-layer track group includes two first slider groups and a second guide rail respectively matched with the first guide rails, the second guide rail is fixed to the top surfaces of the two first slider groups and the length direction of the second guide rail is arranged along the Y-axis direction, the third-layer track group includes a second slider group matched with the second guide rail, a second connecting rod is fixed on the top of the second slider group, and both ends of the second connecting rod are respectively hinged to the other ends of the two pulling systems, the structure of the XY slide rail system is concretized, and the structure is simple and easy to implement.

[0009] Furthermore, a track group of one layer also includes a first connecting plate, and the two first guide rails are respectively fixed to the two ends of the first connecting plate in the Y-axis direction, so that the two first guide rails can be directly fixed to the top surface of the structure through the first connecting plate.

[0010] Furthermore, each first slider group includes two first sliders distributed along the X-axis direction and a second connecting plate, each second connecting plate is fixed to the top surface of the corresponding two first sliders, the two second connecting plates are integrally connected through the first connecting rods arranged along the Y-axis direction in their length direction, and the second guide rail is fixedly connected to the top surface of the first connecting rod. The structure of the two-layer track group is specific, standardized and more stable.

[0011] Furthermore, the second slider group includes two second sliders, a second connecting block is fixed on the top of each second slider, two end portions of the second connecting rod pass through the two connecting blocks and are respectively fixed to the two connecting blocks, two ends of the second connecting rod are fixed with hanging rings, and a suspension wing plate is fixed on each connecting block, and pulling wires are arranged between the two ends of the suspension wing plate in the X-axis direction and the hanging rings. The structural design of the suspension wing plate and the pulling wire can significantly improve the bending stiffness of the second connecting rod, thereby avoiding severe bending of the second connecting rod when pulling on both sides, thereby affecting the test results.

[0012] Furthermore, each pulling system includes a hand chain hoist, a force measuring rod, and a wire rope connected in sequence, the end of the wire rope not connected to the force measuring rod is hinged to the lifting ring on one end of the second connecting rod, and the hook ring on the hand chain hoist is hinged to the corresponding reaction wall. When the pure torque is input through the pulling system, it is only necessary to pull the hand chain hoist respectively, and the structure of the pulling system is specific, simple and practical.

[0013] Furthermore, the force measuring rod includes a steel rod, a strain gauge, and two connecting rings. The strain gauge is attached to the surface of the steel rod, and the two connecting rings are respectively fixed to the two ends of the steel rod. The structure of the force measuring rod is simple and practical, and the two connecting rings are convenient for connecting with the wire rope and the hand winch.

[0014] Furthermore, both ends of the two first guide rails and the second guide rail are provided with limit plugs to prevent the first slider and the second slider from sliding out of the first guide rail and the second guide rail when sliding.

[0015] Furthermore, the steel wire rope is connected to the corresponding lifting rings of the second connecting rod by a spring buckle, so as to facilitate the switching of the connection positions of the pulling system and the lifting rings at both ends of the second connecting rod when the torque is input in the reverse direction.

[0016] The beneficial effects produced by the present invention are as follows: the loading device described in the present invention cleverly utilizes the characteristics of the XY slide rail system to release the translational freedom of the loading device in the XY direction of the horizontal plane, so that the loading device can deform along with the structure when torque loading is performed without generating any external force other than torque, so as to cope with the change in the spatial position of the loading device during the translational and torsional coupling deformation of the structure, thereby realizing a low-cycle reciprocating pure torsion test of the structure, eliminating the interference of the uncertain position of the torsional rigid center of the structure on the test, and can be applied to the torsional performance research of any structure, and the device has a simple structure and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 It is a schematic diagram of the overall structure of the loading device described in the present invention;

[0020] Figure 2 It is a schematic diagram of the use state of the loading device described in the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of a track group;

[0022] Figure 4 It is a schematic diagram of the structure of the second-layer track group;

[0023] Figure 5 It is a schematic diagram of the structure of a three-layer track group;

[0024] Figure 6 is a schematic diagram of the assembly structure of the second connecting rod and the connecting block;

[0025] Figure 7 It is a simplified schematic diagram of the device of the present invention when the torque is input clockwise;

[0026] Figure 8 It is a simplified schematic diagram of the device of the present invention when torque is input counterclockwise.

[0027] In the figure: 1-one-layer track group, 11-first guide rail, 12-first connecting plate, 2-two-layer track group, 21-first slider, 22-second guide rail, 23-second connecting plate, 24-first connecting rod, 3-three-layer track group, 31-second slider, 32-connecting block, 33-second connecting rod, 34-lifting ring, 35-hanging wing plate, 36-pulling wire, 4-reaction wall, 5-pulling system, 51-hand winch, 52-force measuring rod, 53-wire rope, 54-connecting ring, 6-structure. DETAILED DESCRIPTION

[0028] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. 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.

[0029] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0031] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0032] like Figure 1 , 2 As shown in Figures 3, 4, 5 and 6, a loading device suitable for a low-cycle reciprocating pure torsion test comprises an XY slide rail system, two reaction walls 4 arranged side by side along the X-axis direction, and two pulling systems 5 with force measuring functions, wherein the XY slide rail system comprises a first-layer track group 1, a second-layer track group 2 and a third-layer track group 3, the XY slide rail system is located between the two reaction walls 4, the first-layer track group 1 is arranged along the X-axis direction, the second-layer track group 2 is slidably connected to the first-layer track group 1 along the X-axis direction, and the third-layer track group 3 is slidably connected to the second-layer track group 2 along the Y-axis direction, one end of the two pulling systems 5 are respectively hinged to the two reaction walls 4, the other ends of the two pulling systems 5 are respectively hinged to the two ends of the three-layer track group 3 in the Y-axis direction, the two pulling systems 5 are arranged in parallel and the angle between each pulling system 5 and the three-layer track group 3 is an acute angle.

[0033] Principle description: The loading device utilizes the sliding characteristics of the XY slide rail system to release the translational freedom of the loading device in the XY direction of the horizontal plane, so that the loading device can separate the translational and torsional external force inputs when torque loading is performed on the structure 6, and release the translational external force through the XY slide rail system, so that when the loading device follows the structure 6 to undergo translational and torsional coupling deformation, no other external force inputs such as translational external force are generated except torque, thereby realizing a low-cycle reciprocating pure torsion test of the structure 6.

[0034] During installation, the loading device is fixed to the structure by fixing a layer of track group 1 of the loading device to the top surface of the structure 6 (how to fix a layer of track group 1 to the top surface of the structure 6 is common knowledge of those skilled in the art, and can be fixed by bonding or bolting). At the same time, torsion sensors are respectively installed on the pulling systems 5 on both sides and the structure 6. The layers of the XY slide rail system are slidingly connected in the X-axis direction and the Y-axis direction, and the Z-axis rotational degree of freedom is constrained. After the pure torque is input to the three-layer track group 3 through the pulling system 5, the pure torque will be transmitted downward to the structure 6 layer by layer. If relative sliding occurs between the track groups of each layer, it indicates that the rigid center and the center of mass of the structure 6 do not coincide, and the structure 6 to be tested exhibits a deformation of transverse torsion coupling under pure torque; if there is no relative sliding between the track groups of each layer, it indicates that the rigid center and the center of mass of the structure 6 to be tested coincide, and the structure 6 only undergoes torsional deformation. Therefore, when calculating the input pure torque, only the top three-layer track group 3 and the pulling system 5 need to be concerned.

[0035] Take clockwise input torque as an example, Figure 7As shown, the three-layer track group 3 is simplified to the line segment BC, and the traction system 5 on both sides is simplified to the line segments AB and CD, and the points A and D are the hinge points of the reaction wall 4. When the traction system 5 on both sides is loaded with torque, AB and CD are shortened and apply a force F to both ends of BC to rotate BC, and this pair of forces F always only forms a torque, that is, even if AB' and C'D are no longer of equal length after rotation and shortening, they always remain parallel and have equal tension. The value of the force F can be measured by the force measuring rod 52 in the traction system 5, and the torsion angles α, β, and γ of BC, AB, and CD can be measured by installing torsion sensors on the traction system 5 on both sides and the structure 6.

[0036] It is known that the length of BC is t, and the angle between AB and BC in the initial state is , angle between CD and BC , when BC rotates clockwise to B'C', the angle between AB' and B'C' is , angle between C'D and B'C' ,at this time , and the forces F on both sides are equal, indicating that the test is a low-cycle reciprocating pure torsion test.

[0037] Calculate the torque value T when the clockwise input torque is obtained

[0038]

[0039] or

[0040]

[0041] The counterclockwise input torque is opposite to the clockwise input torque, e.g. Figure 8 As shown, during the test, it is only necessary to swap the connection positions of the pulling systems 5 on both sides and the lifting rings 34 at both ends of the second connecting rod 33. The calculation method of the torque value is the same as that when the torque is input clockwise, and the formula is the same, thereby completing the low-cycle reciprocating pure torsion test of the structure 6.

[0042] In specific implementation, the first-layer track group 1 includes two first guide rails 11 whose length direction is arranged along the X-axis direction and distributed side by side, the second-layer track group 2 includes two first slider groups respectively matched with the first guide rails 11 and a second guide rail 22, the second guide rail 22 is fixed to the top surfaces of the two first slider groups and the length direction of the second guide rail 22 is arranged along the Y-axis direction, the third-layer track group 3 includes a second slider group matched with the second guide rail 22, a second connecting rod 33 is fixed on the top of the second slider group, and the two ends of the second connecting rod 33 are respectively hinged to the other ends of the two pulling systems 5, the structure of the XY slide rail system is concretized, the structure is simple and easy to implement.

[0043] In specific implementation, a track group 1 also includes a first connecting plate 12 , and the two first guide rails 11 are respectively fixed to the two ends of the first connecting plate 12 in the Y-axis direction, so that the two first guide rails 11 can be directly fixed to the top surface of the structure 6 through the first connecting plate 12 .

[0044] In specific implementation, each first slider group includes two first sliders 21 distributed along the X-axis direction and a second connecting plate 23, each second connecting plate 23 is fixed to the top surface of the corresponding two first sliders 21, the two second connecting plates 23 are integrally connected through the first connecting rod 24 arranged along the Y-axis direction in the length direction thereof, and the second guide rail 22 is fixedly connected to the top surface of the first connecting rod 24. The structure of the second-layer track group 2 is specific, standardized and more stable.

[0045] In specific implementation, the second slider group includes two second sliders 31, and a connecting block 32 is fixed on the top of each second slider 31. The two ends of the second connecting rod 33 pass through the two connecting blocks 32 and are respectively fixed to the two connecting blocks 32. Both ends of the second connecting rod 33 are fixed with hanging rings 34. Each connecting block 32 is fixed with a hanging wing plate 35. Both ends of the hanging wing plate 35 in the X-axis direction are provided between the hanging rings 34. The structural design of the hanging wing plate 35 and the pulling wire 36 can significantly improve the bending stiffness of the second connecting rod 33, thereby avoiding severe bending of the second connecting rod 33 when pulling on both sides, thereby affecting the test results.

[0046] In specific implementation, each pulling system 5 includes a hand chain hoist 51, a force measuring rod 52, and a wire rope 53 connected in sequence. The end of the wire rope 53 not connected to the force measuring rod 52 is hinged to the lifting ring 34 on one end of the second connecting rod 33, and the hook ring on the hand chain hoist 51 is hinged to the corresponding reaction wall 4. When the pure torque is input through the pulling system 5, it is only necessary to pull the hand chain hoist 51 respectively. The structure of the pulling system 5 is specific, simple, and practical.

[0047] During specific implementation, the force measuring rod 52 includes a steel rod, a strain gauge, and two connecting rings 54. The strain gauge is attached to the surface of the steel rod, and the two connecting rings 54 are respectively fixed to the two ends of the steel rod. The structure of the force measuring rod 52 is simple and practical, and the two connecting rings 54 are convenient for connecting with the wire rope 53 and the hand winch 51.

[0048] In a specific implementation, both ends of the two first guide rails 11 and the second guide rail 22 are provided with limit plugs to prevent the first slider 21 and the second slider 31 from sliding out of the first guide rail 11 and the second guide rail 22 when sliding.

[0049] In this specific embodiment, the steel wire rope 53 is connected to the corresponding rings 34 of the second connecting rod 33 by a spring buckle, so as to facilitate the switching of the connection positions of the pulling system 5 and the rings 34 at both ends of the second connecting rod 33 when the torque is input in the opposite direction.

[0050] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A loading device suitable for low-cycle reciprocating pure torsion test, characterized in that: The invention comprises an XY slide rail system, two reaction force walls (4) arranged side by side along the X-axis direction, and two pulling systems (5) with force measurement functions. The XY slide rail system comprises a first-layer track group (1), a second-layer track group (2), and a third-layer track group (3). The XY slide rail system is located between the two reaction force walls (4). The first-layer track group (1) is fixed to the top surface of the structure. The first-layer track group (1) comprises two first guide rails (11) whose length direction is arranged along the X-axis direction and are arranged side by side. The second-layer track group (2) comprises two first slider groups respectively matched with the first guide rails (11) and a second guide rail (2 2), the second guide rail (22) is fixed to the top surface of the two first slider groups and the length direction of the second guide rail (22) is arranged along the Y-axis direction, the three-layer track group (3) includes a second slider group adapted to the second guide rail (22), a second connecting rod (33) is fixed to the top of the second slider group, one end of the two pulling systems (5) is respectively hinged to the two reaction walls (4), the other ends of the two pulling systems (5) are respectively hinged to the two ends of the second connecting rod (33), the two pulling systems (5) are arranged in parallel and the angle between each pulling system (5) and the three-layer track group (3) is an acute angle.

2. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 1, characterized in that: The one-layer track group (1) further comprises a first connecting plate (12), and the two first guide rails (11) are respectively fixed to two end portions of the first connecting plate (12) in the Y-axis direction.

3. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 2, characterized in that: Each first slider group comprises two first sliders (21) distributed along the X-axis direction and a second connecting plate (23); each second connecting plate (23) is fixed to the top surface of the corresponding two first sliders (21); the two second connecting plates (23) are integrally connected via a first connecting rod (24) arranged along the Y-axis direction in their length direction; and the second guide rail (22) is fixedly connected to the top surface of the first connecting rod (24).

4. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 3, characterized in that: The second slider group comprises two second sliders (31), a connecting block (32) is fixed to the top of each second slider (31), two ends of a second connecting rod (33) pass through the two connecting blocks (32) and are fixed to the two connecting blocks (32), two ends of the second connecting rod (33) are fixed with hanging rings (34), each connecting block (32) is fixed with a hanging wing plate (35), and pulling steel wires (36) are arranged between the two ends of the hanging wing plate (35) in the X-axis direction and the hanging ring (34).

5. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 4, characterized in that: Each pulling system (5) comprises a hand chain hoist (51), a force measuring rod (52), and a steel wire rope (53) which are connected in sequence. The end of the steel wire rope (53) which is not connected to the force measuring rod (52) is hinged to a lifting ring (34) on one end of the second connecting rod (33). The hook ring on the hand chain hoist (51) is hinged to the corresponding reaction wall (4).

6. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 5, characterized in that: The force measuring rod (52) comprises a steel rod, a strain gauge, and two connecting rings (54), wherein the strain gauge is attached to the surface of the steel rod, and the two connecting rings (54) are respectively fixed to two ends of the steel rod.

7. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 6, characterized in that: Limit plugs are provided at both ends of the two first guide rails (11) and the second guide rail (22).

8. A loading device suitable for low-cycle reciprocating pure torsion test according to claim 7, characterized in that: The steel wire rope (53) is connected to the lifting ring (34) corresponding to the second connecting rod (33) via a spring buckle.

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