Support structure for test specimen in concrete beam bending experiment

Abstract

The present application relates to the test piece support structure in concrete beam bending experiment, including orthogonal hinge support and sliding hinge support, the sliding hinge support includes support upper plate and support lower plate, the top surface of support lower plate and along its length direction is equipped with the rolling groove with the sector shape cross section, the inside of rolling groove is equipped with the support shaft that is combined with support upper plate bottom, a plurality of rollable needle is equipped between support shaft and rolling groove inner wall, the moving buffer mechanism is equipped between support upper plate and support lower plate. The test piece support structure in concrete beam bending experiment, two pieces of test piece are supported by a sliding hinge support and an orthogonal hinge support respectively, the top of support is plate type structure, and has certain contact surface with test piece, which can reduce contact stress, prevent test piece from being damaged, and when test piece is elongated, the support shaft can rotate, a plurality of needle rotates and moves, is supported by the moving buffer mechanism, and the support span is not changed.

Description

Technical Field

[0001] This invention relates to the field of support technology for concrete beam bending tests, specifically a support structure for specimens in concrete beam bending tests. Background Technology

[0002] Bending deformation is a key topic in mechanics of materials and the foundation upon which commonly used theories in engineering design (normal stress formula, deflection curve integral equation, etc.) are established. Whether the establishment of a "mechanical model," namely the "plane assumption," "small deformation assumption," and ideal constraints such as supports and fixed ends, correctly reflects reality depends on experimental verification. The purpose of the experiment is to examine the mechanical basis of the beam through experiments.

[0003] In the bending test of concrete beams, it is required that a fixed hinge support be used at one end and a sliding hinge support be used at the other end. Generally, simple supports are used. The fixed hinge support is held in place by an angle iron, and the sliding hinge support is held in place by a round shaft or steel pipe. This approach has the following problems:

[0004] 1) The contact point between the support and the specimen is a line contact, and the stress and deformation at the contact point are relatively large, which will cause a large stress zone in the support, making it inconvenient to test, and may even lead to local damage to the specimen;

[0005] 2) The support does not have the ability to deform outward. If the surface of the concrete beam specimen is uneven, it may be that the surface of the specimen cannot form line contact with two supports at the same time, and one corner will be raised.

[0006] 3) The specimen will elongate during the experiment, and the sliding support will move accordingly, resulting in a change in the span.

[0007] Based on the above problems, this application proposes a specimen support structure for bending tests of concrete beams to solve the above problems. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a specimen support structure for concrete beam bending tests. This specimen support structure consists of a sliding hinge support and an orthogonal hinge support supporting the two parts of the specimen respectively. The top of the support is a plate structure with a certain contact surface with the specimen, which can reduce contact stress and prevent damage to the specimen. At the same time, even when the specimen surface is uneven or the specimen undergoes elongation deformation, it can still ensure that the specimen is in overall contact and the span does not change.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a specimen support structure for a concrete beam bending test, comprising an orthogonal hinge support and a sliding hinge support for supporting both ends of the specimen, wherein the orthogonal hinge support comprises a support top plate, a support middle plate, and a support bottom plate arranged sequentially from top to bottom; the support middle plate and the support top plate are provided with fan-shaped top fixing grooves on opposite sides along their length; a rotation X-axis is rotatably arranged within the space formed by the two top fixing grooves; a top balance buffer mechanism is provided between the support middle plate and the support top plate; the support middle plate and the support bottom plate are provided with fan-shaped bottom fixing grooves on opposite sides along their width; a rotation Z-axis is rotatably arranged within the space formed by the two bottom fixing grooves; and a bottom balance buffer mechanism is provided between the support middle plate and the support bottom plate.

[0010] The sliding hinge support includes an upper support plate and a lower support plate distributed vertically. The top surface of the lower support plate has a fan-shaped rolling groove along its length. A support shaft is rotatably arranged inside the rolling groove and fits against the bottom surface of the upper support plate. Multiple rolling needles are provided between the support shaft and the inner wall of the rolling groove. A moving buffer mechanism is provided between the upper support plate and the lower support plate.

[0011] Furthermore, the central axis of the rotating X-axis is collinear with the central axes of the two top fixing slots, and the rotating X-axis is in contact with the inner walls of the two top fixing slots. The central axis of the rotating Z-axis is collinear with the central axes of the two bottom fixing slots, and the rotating Z-axis is in contact with the inner walls of the two bottom fixing slots.

[0012] Furthermore, the central axis of the support shaft and the central axis of the rolling groove are located on the same straight line, and a plurality of the roller needles are equidistantly distributed in the rolling groove along the outer circumference of the support shaft with the central axis of the support shaft as the center. The roller needles are in close contact with the outer wall of the support shaft and the inner wall of the rolling groove.

[0013] Furthermore, the top balance buffer mechanism includes four No. 1 tension springs, and two No. 1 hangers are vertically fixed on both the left and right sides of the support top plate and the support middle plate. The two ends of the No. 1 tension springs are respectively hung on the two corresponding No. 1 hangers.

[0014] Furthermore, the No. 1 tension spring located on the front and the No. 1 tension spring located on the back are symmetrical about the rotation X-axis, and the No. 1 tension spring is vertically downward in the normal state.

[0015] Furthermore, the bottom balance buffer mechanism includes two bidirectional tension and compression springs. Two receiving grooves are provided on opposite sides of the support middle plate and the support bottom plate. The two ends of the bidirectional tension and compression springs extend into their corresponding receiving grooves and are fixed to the inner wall of the receiving grooves on the side away from the bidirectional tension and compression springs.

[0016] Furthermore, the two upper receiving slots and the two lower receiving slots are symmetrical to each other, while the two left receiving slots and the two right receiving slots are symmetrical to each other about the rotation Z-axis.

[0017] Furthermore, the movable buffer mechanism includes four No. 2 tension springs, and two No. 2 hangers are vertically fixed on both the left and right sides of the upper and lower support plates. The upper and lower ends of the No. 2 tension springs are respectively hung on the two corresponding No. 2 hangers.

[0018] Furthermore, the No. 2 tension spring located on the front and the No. 2 tension spring located on the back are symmetrical about the support axis, and the No. 2 tension spring is vertically downward in the normal state.

[0019] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0020] In this concrete beam bending test, the specimen support structure consists of a sliding hinge support and an orthogonal hinge support supporting the two parts of the specimen respectively. The top of the support is a plate structure with a certain contact surface with the specimen, which can reduce contact stress and prevent damage to the specimen. At the same time, when the specimen surface is uneven and there is out-of-plane warping, the top plate and the middle plate of the support can tilt. The top and bottom balancing buffer mechanisms provide buffer support to ensure that the specimen is in overall contact with the support surface, reducing contact stress and preventing damage to the specimen. Furthermore, when the specimen undergoes elongation deformation, the support shaft can rotate, and multiple needle rollers rotate and move. The moving buffer mechanism provides buffer support to ensure that the span of the support does not change. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a side view of the orthogonal hinge support of the present invention;

[0023] Figure 3 This is a side view of the sliding hinge support of the present invention;

[0024] Figure 4 This is a schematic diagram of the orthogonal hinge support in this invention when the surface of the specimen is uneven and there is out-of-plane warping.

[0025] Figure 5 This is a schematic diagram of the sliding hinge support surface of the present invention undergoing elongation deformation on the specimen.

[0026] In the diagram: 101 Support top plate, 102 No. 1 hanger rod, 103 No. 1 tension spring, 104 Support middle plate, 105 Receiving groove, 106 Tension and compression double spring, 107 Support bottom plate, 108 Rotation Z-axis, 109 Bottom fixing groove, 110 Top fixing groove, 111 Rotation X-axis, 201 Support upper plate, 202 No. 2 hanger rod, 203 No. 2 tension spring, 204 Support lower plate, 205 Support shaft, 206 Rolling groove, 207 Needle roller. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1-3 In this embodiment, the specimen support structure in the concrete beam bending test includes an orthogonal hinge support and a sliding hinge support, which are used to support the two ends of the specimen respectively. The orthogonal hinge support and the sliding hinge support are generally used in pairs.

[0029] The orthogonal hinge support includes a support top plate 101, a support middle plate 104, and a support bottom plate 107 arranged sequentially from top to bottom. The support middle plate 104 and the support top plate 101 each have a fan-shaped top fixing groove 110 along their length on opposite sides. A rotation X-axis 111 is rotatably mounted within the space formed by the two top fixing grooves 110. The central axis of the rotation X-axis 111 is collinear with the central axes of the two top fixing grooves 110. The rotation X-axis 111 is in contact with the inner walls of both top fixing grooves 110. The support middle plate 107... A top balance buffer mechanism is provided between the support top plate 104 and the support bottom plate 107. On the opposite side of the support middle plate 104 and the support bottom plate 107, a bottom fixing groove 109 with a fan-shaped cross section is provided along its width direction. A rotating Z-axis 108 is rotatably arranged in the space formed by the two bottom fixing grooves 109. The central axis of the rotating Z-axis 108 is on the same straight line as the central axis of the two bottom fixing grooves 109. The rotating Z-axis 108 is in contact with the inner wall of the two bottom fixing grooves 109. A bottom balance buffer mechanism is provided between the support middle plate 104 and the support bottom plate 107.

[0030] It should be noted that the inner bottom walls of the top fixing groove 110 and the bottom fixing groove 109 are vertically fixed with first support plates near their left and right sides. The rotating X-axis 111 and the rotating Z-axis 108 are located between the two first support plates in the top fixing groove 110 and the bottom fixing groove 109, respectively. The rotating X-axis 111 and the rotating Z-axis 108 are rotatably connected to the first support plates through bearings.

[0031] During the experiment, when the specimen surface is uneven and exhibits out-of-plane warping, both the top plate 101 and the middle plate 104 of the support can tilt. The top and bottom balancing buffer mechanisms provide cushioning support, ensuring overall contact between the specimen and the support surface, reducing contact stress, and preventing damage to the specimen. For details, please refer to [reference needed]. Figure 4 .

[0032] The sliding hinge support includes an upper support plate 201 and a lower support plate 204 distributed vertically. The top surface of the lower support plate 204 and along its length are provided with a fan-shaped rolling groove 206. Inside the rolling groove 206, a support shaft 205 is rotatably mounted and fits against the bottom surface of the upper support plate 201. The central axis of the support shaft 205 and the central axis of the rolling groove 206 are on the same straight line. Between the support shaft 205 and the inner wall of the rolling groove 206, there are multiple rolling needles 207. The multiple needles 207 are equidistantly distributed in the rolling groove 206 along the outer circumference of the support shaft 205 with the central axis of the support shaft 205 as the center. The needles 207 are in close contact with the outer wall of the support shaft 205 and the inner wall of the rolling groove 206. A moving buffer mechanism is provided between the upper support plate 201 and the lower support plate 204.

[0033] It should be noted that the inner bottom wall of the rolling groove 206 and near its left and right sides are vertically fixed with second support plates. The support shaft 205 is located between the two second support plates. The two ends of the support shaft 205 are rotatably connected to the two second support plates through bearings. The needle roller 207 is located between the two second support plates.

[0034] During the experiment, when the specimen undergoes elongation deformation, the support shaft 205 can rotate, and multiple needle rollers 207 rotate and move. A moving buffer mechanism provides cushioning support, ensuring that the support span remains unchanged. For details, please refer to [reference needed]. Figure 5 .

[0035] The top balance buffer mechanism includes four tension springs 103. Two suspension rods 102 are vertically fixed on both the left and right sides of the support top plate 101 and the support middle plate 104. The two ends of the tension springs 103 are respectively hung on the two corresponding suspension rods 102.

[0036] Among them, the No. 1 tension spring 103 located on the front and the No. 1 tension spring 103 located on the back are symmetrical about the rotation X-axis 111. The No. 1 tension spring 103 is vertically downward in the normal state. When the support top plate 101 tilts back and forth, the No. 1 tension spring 103 on one side will be squeezed, while the No. 1 tension spring 103 on the other side will be compressed. The tension generated by the No. 1 tension springs 103 on both sides can provide buffer support.

[0037] The bottom balance buffer mechanism includes two bidirectional tension and compression springs 106. The support middle plate 104 and the support bottom plate 107 each have two receiving grooves 105 on their opposite sides. The two ends of the bidirectional tension and compression springs 106 extend into their corresponding receiving grooves 105 and are fixed to the inner wall of the receiving grooves 105 away from the bidirectional tension and compression springs 106.

[0038] The two upper and two lower receiving slots 105 are symmetrical to each other. At the same time, the two left and two right receiving slots 105 are symmetrical to each other with the rotation Z-axis 108 as the center. When the support middle plate 104 is tilted to the left or right under the force, the tension-compression bidirectional spring 106 on one side is compressed and the tension-compression bidirectional spring 106 on the other side is stretched. The tension generated by the tension-compression bidirectional springs 106 on both sides provides buffer support.

[0039] The movable buffer mechanism includes four No. 2 tension springs 203. Two No. 2 hangers 202 are vertically fixed on the left and right sides of the upper support plate 201 and the lower support plate 204. The upper and lower ends of the No. 2 tension springs 203 are respectively hung on the two corresponding No. 2 hangers 202.

[0040] Among them, the No. 2 tension spring 203 located on the front and the No. 2 tension spring 203 located on the back are symmetrical about the support shaft 205. Under normal conditions, the No. 2 tension spring 203 is vertically downward. When the upper plate 201 of the support is displaced, the support shaft 205 can rotate, and multiple needle rollers 207 rotate and move, and the No. 2 tension spring 203 is stretched. The tension generated by the No. 2 tension spring 203 provides buffer support.

[0041] The working principle of the above embodiments is as follows:

[0042] When the specimen surface is uneven and out-of-plane warping occurs, both the support top plate 101 and the support middle plate 104 can tilt. When the support top plate 101 tilts back and forth, the No. 1 tension spring 103 on one side will be compressed, while the No. 1 tension spring 103 on the other side will be compressed. The tension generated by the No. 1 tension springs 103 on both sides can provide buffer support. When the support middle plate 104 tilts left and right under force, the double-tension spring 106 on one side will be compressed, while the double-tension spring 106 on the other side will be stretched. The tension generated by the double-tension springs 106 on both sides can provide buffer support, ensuring that the specimen is in overall contact with the support surface, reducing contact stress and preventing damage to the specimen. When the specimen undergoes elongation deformation, the support shaft 205 can rotate, multiple needle rollers 207 rotate and move, the support upper plate 201 will be displaced, and the No. 2 tension springs 203 will be stretched. The tension generated by the No. 2 tension springs 203 can provide buffer support, ensuring that the support span does not change.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A support structure for a concrete beam bending test specimen, characterized in that, The system includes an orthogonal hinge support and a sliding hinge support for supporting both ends of the specimen. The orthogonal hinge support comprises a support top plate (101), a support middle plate (104), and a support bottom plate (107) arranged sequentially from top to bottom. The support middle plate (104) and the support top plate (101) each have a fan-shaped top fixing groove (110) along their length on opposite sides. A rotation X-axis (111) is rotatably arranged within the space formed by the two top fixing grooves (110). A top balancing buffer mechanism is provided between the support middle plate (104) and the support top plate (101). The support middle plate (104) and the support bottom plate (107) each have a fan-shaped bottom fixing groove (110) along their width on opposite sides. 09), a rotating Z-axis (108) is rotatably provided in the space formed by the two bottom fixing grooves (109), and a bottom balance buffer mechanism is provided between the support middle plate (104) and the support bottom plate (107); the sliding hinge support includes a support upper plate (201) and a support lower plate (204) distributed vertically, and a fan-shaped rolling groove (206) is provided on the top surface of the support lower plate (204) along its length direction, and a support shaft (205) is rotatably provided inside the rolling groove (206) and fits against the bottom surface of the support upper plate (201), and multiple rolling needles (207) are provided between the support shaft (205) and the inner wall of the rolling groove (206), and a moving buffer mechanism is provided between the support upper plate (201) and the support lower plate (204); The central axis of the rotating X-axis (111) is on the same straight line as the central axis of the two top fixing grooves (110), and the inner walls of the rotating X-axis (111) and the two top fixing grooves (110) are in contact. The central axis of the rotating Z-axis (108) is on the same straight line as the central axis of the two bottom fixing grooves (109), and the inner walls of the rotating Z-axis (108) and the two bottom fixing grooves (109) are in contact. The central axis of the support shaft (205) and the central axis of the rolling groove (206) are on the same straight line. Multiple needle rollers (207) are equidistantly distributed in the rolling groove (206) around the central axis of the support shaft (205) along its outer circumference. The needle rollers (207) are in close contact with the outer wall of the support shaft (205) and the inner wall of the rolling groove (206).

2. The specimen support structure for the bending test of a concrete beam according to claim 1, characterized in that: The top balance buffer mechanism includes four No. 1 tension springs (103). Two No. 1 hangers (102) are vertically fixed on the left and right sides of the support top plate (101) and the support middle plate (104). The two ends of the No. 1 tension springs (103) are respectively hung on the two corresponding No. 1 hangers (102) above and below.

3. The specimen support structure for the bending test of a concrete beam according to claim 2, characterized in that: The first tension spring (103) located on the front and the first tension spring (103) located on the back are symmetrical about the rotation X-axis (111). The first tension spring (103) is vertically downward in the normal state.

4. The specimen support structure in the bending test of a concrete beam according to claim 1, characterized in that: The bottom balance buffer mechanism includes two bidirectional tension and compression springs (106). Two receiving grooves (105) are provided on opposite sides of the support middle plate (104) and the support bottom plate (107). The two ends of the bidirectional tension and compression springs (106) extend into the corresponding receiving grooves (105) and are fixed to the inner wall of the receiving grooves (105) away from the bidirectional tension and compression springs (106).

5. The specimen support structure for the bending test of a concrete beam according to claim 4, characterized in that: The two upper receiving slots (105) and the two lower receiving slots (105) are symmetrical to each other. Meanwhile, the two left receiving slots (105) and the two right receiving slots (105) are symmetrical to each other about the rotation Z-axis (108).

6. The specimen support structure for the bending test of a concrete beam according to claim 1, characterized in that: The movable buffer mechanism includes four No. 2 tension springs (203). Two No. 2 hangers (202) are vertically fixed on the left and right sides of the upper plate (201) and lower plate (204) of the support. The upper and lower ends of the No. 2 tension springs (203) are respectively hung on the two corresponding No. 2 hangers (202).

7. The specimen support structure for the bending test of a concrete beam according to claim 6, characterized in that: The second tension spring (203) located on the front and the second tension spring (203) located on the back are symmetrical about the support shaft (205). The second tension spring (203) is vertically downward in the normal state.

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