End part reinforcing teaching aid for compression experiment of cold-formed section steel test piece

Abstract

The invention relates to the technical field of civil engineering teaching aids, in particular to an end reinforcing teaching aid for a compression experiment of a cold-formed section steel test piece, and the end reinforcing teaching aid is composed of a reinforcing frame, a supporting bolt, a locking nut and supporting cushion blocks with different sizes. The device is in close contact with the cold-formed section steel pressure-bearing test piece through the supporting cushion block to reinforce the end part of the test piece. Slotted holes are formed in the long edges and the short edges of the reinforcing frame, bolts can conveniently penetrate through the slotted holes, the positions of the bolts are reasonably adjusted according to the size of a test piece, meanwhile, blind holes are formed in the middle points of the long edges, and the reinforcing frame is allowed to be split into two parts for use through the blind holes. The supporting bolt penetrates through the slotted hole and the blind hole in the reinforcing frame and then is fixed to the reinforcing frame through the two locking nuts, and transverse force is applied to the supporting cushion block so as to prevent the cushion block from being separated from the test piece. The reinforcing device can be used for reinforcing the end parts of pressed test pieces with different section types and different section sizes by selecting proper supporting cushion blocks and reasonably adjusting the lengths and the positions of bolts.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering teaching aids, and in particular to an end reinforcement teaching aid for a compression test of a cold-bent steel specimen. Background Art

[0002] Cold-formed steel structures have many advantages such as light weight, high strength, short construction period, and high degree of industrialization. They are widely used in the design and construction of small and medium-sized industrial plants, light steel structure houses and other structures. In the field of cold-formed steel testing, specimen compression is a common loading condition. The loading process is generally as follows: place an end plate at the upper and lower ends respectively (long columns require welded end plates), apply load to the end plates through an axial compression testing machine to load the specimen, record the test data during the loading process, and observe the mechanical properties of the specimen under pressure. Because the end of the cold-formed steel specimen is in direct contact with the end plate in the compression test, the force is complex, which makes it easy for the end of the specimen to be partially damaged in advance, thereby affecting the accuracy of the test results, and even causing the test to fail.

[0003] However, the investigation found that there is still no device specifically used to prevent the end damage of cold-formed steel specimens in compression tests. Therefore, a simple-structured and feasible-operation end reinforcement teaching aid for cold-formed steel specimen compression tests is designed. It is used to effectively reinforce the ends of cold-formed steel specimens in compression tests, and has good applicability in terms of specimen cross-section (C-type, U-type, H-type, square-rectangular type, etc.), compression form (axial compression and eccentric compression), specimen type (long column, short column), etc., and will have strong practical significance for improving the accuracy of cold-formed steel specimen compression test results. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and provide a cold-bent steel pressure specimen end reinforcement device, which can conveniently and effectively reinforce the end of the pressure specimen to ensure that it will not be damaged in advance during the loading process. The test device is suitable for various cross-sections such as C-type, U-type, H-type, square and rectangular cross-sections, and is also suitable for the reinforcement of columns of various lengths.

[0005] To achieve the above-mentioned purpose, the present invention provides an end reinforcement teaching aid for a compression test of a cold-bent steel specimen, comprising: two reinforcement frames, the reinforcement frames are respectively arranged at the upper end and the lower end of the cold-bent steel specimen, the reinforcement frames include a first reinforcement frame and a second reinforcement frame, the first reinforcement frame and the second reinforcement frame are U-shaped, and the first reinforcement frame and the second reinforcement frame are rectangular after splicing, the plane where the reinforcement frame is located is perpendicular to the axis of the cold-bent steel specimen, and the reinforcement frame is arrayed around a plurality of penetrating support bolts, the support bolts tighten the support pads to the surface of the cold-bent steel specimen, and the support bolts are tightly connected to the reinforcement frame through two locking nuts.

[0006] Preferably: the reinforcement frame is provided with strip-shaped slot holes on its circumferential sides, the hole height of the slot holes being the same as the diameter of the support bolts, providing lateral sliding space for the support bolts passing through the slot holes to adapt to the reinforcement requirements of cross-sections of different sizes, while limiting the support bolts in the vertical direction.

[0007] Preferably: both ends of the first reinforcement frame and the second reinforcement frame are step structures, and the first reinforcement frame and the second reinforcement frame are overlapped by the step structure, and a penetrating blind hole is also provided at the overlap, and the blind hole is used for the support bolt to pass through.

[0008] Preferably, the support bolts include transverse support bolts and longitudinal support bolts, the transverse support bolts are arranged in the slot holes on the short sides of the reinforcement frame, and the longitudinal support bolts are arranged in the slot holes and the blind holes on the short sides of the reinforcement frame.

[0009] Preferably, the transverse support bolt and the longitudinal support bolt pass through the slotted hole or the blind hole and abut against the support pad, thereby providing horizontal support force for the support pad.

[0010] Preferably, the size of the support pad matches the cross section of the cold-bent steel specimen.

[0011] Preferably, the hardness of the support bolt is greater than that of the support pad, the front end of the support bolt can be embedded in the surface of the support pad and the support pad can maintain a working state.

[0012] Compared with the prior art, the technical solution proposed in the present application has the following beneficial effects: the deformation of the end of the cold-bent steel compression specimen is limited by the support pad, thereby preventing the end of the specimen from being damaged in advance, and further preventing the influence of the damage of the end of the specimen on the compression test of the cold-bent steel specimen; the reinforcement frame adopts the form of slots on both the long and short sides, which is convenient for adjusting the position of the support bolts at any time; at the same time, it can be divided into two parts at the blind hole at the midpoint of the long side, and the two parts can be merged together by inserting the support bolts at the blind hole, making the operation of the entire device more convenient and more flexible; there is no limit on the size of the support pad, and the size of the support pad can be reasonably selected according to different cross-sections, so that the device is suitable for the end reinforcement of cold-bent steel compression specimens with different cross-section types such as C-type, U-type, H-type and square-rectangular; the test device is easy to obtain materials, simple to make, easy to use, good reinforcement effect, and has a wide range of uses. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0014] Figure 1 is a structural diagram of an embodiment of the present invention;

[0015] Figure 2 A top view of an embodiment of the present invention;

[0016] Figure 3 for Figure 2 The AA longitudinal section is shown;

[0017] Figure 4 for Figure 2 The longitudinal section of section BB is shown;

[0018] Figure 5 It is a structural diagram of a reinforcement frame of an embodiment;

[0019] In the figure: 1-reinforcement frame; 2-support bolts; 3-locking nuts; 4-support pads; 5-slot holes; 6-blind holes; 7-cold-bent steel pressure specimens. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe and discuss the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings of the present invention. Obviously, what is described here is only a part of the examples of the present invention, not all the examples. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0023] like Figure 1 , 2As shown, the reinforcement device described in this embodiment can effectively protect the end of the cold-bent steel specimen during the compression test, and mainly includes four parts: a reinforcement frame 1, a support bolt 2, a locking nut 3, and support pads 4 of different sizes. The reinforcement frame 1 is used to provide support for the support bolts 2. When in use, the two parts of the reinforcement frame 1 enclose the C-section cold-bent steel pressure specimen 7 inside the frame; the support bolts 2 pass through the slots 5 on the reinforcement frame 1 to provide lateral support for the support pads 4 of different sizes; the locking nut 3 is used to fix the support bolts 2 on the reinforcement frame 1 to prevent the support bolts 2 from loosening during the reinforcement process; the support pad 4 is in direct contact with the end of the C-section cold-bent steel pressure specimen 7, and with the support of the support bolts 2, the end of the specimen 7 is prevented from being damaged.

[0024] In this embodiment, the reinforcement frame 1 is a rectangular frame. A blind hole 7 is provided at the midpoint of the long side, and the reinforcement frame can be divided into two parts at the blind hole. After the support bolt 2 passes through the blind hole 7, the two parts of the reinforcement frame can be combined together. Strip slots 5 are respectively provided on the long and short sides of the frame, and the hole height is equivalent to the diameter of the support bolt 2, providing a lateral sliding space for the support bolt 2 passing through the slot 5 to meet the reinforcement requirements of different cross-sections, while limiting its movement in the vertical direction.

[0025] In this embodiment, the specification and model of the locking nut 3 matches the supporting bolt 2 and can be screwed into its screw rod.

[0026] In this embodiment, the support bolts 2 are divided into transverse support bolts and longitudinal support bolts. The transverse support bolts pass through the slots on the short sides of the reinforcement frame, and the longitudinal support bolts pass through the slots on the long sides of the reinforcement frame and the blind holes 6 at the midpoints of the long sides. Both the transverse and longitudinal support bolts 2 are hexagonal head full-thread bolts, and their lengths can ensure that the ends are outside the reinforcement frame 1 during reinforcement, which is convenient for use of tools for rotation and adjustment.

[0027] In this embodiment, the support pad 4 is a rectangular parallelepiped, which is in direct contact with the end of the C-shaped cold-formed steel pressure test piece 7 to prevent it from deforming during the compression process. The height, length and width of the support pad 4 are shown in the figure. The width of the pad at the web is greater than that of the pads at other locations, ensuring that the deformation of each surface of the end of the C-shaped cold-formed steel pressure test piece 7 can be effectively restricted.

[0028] In this embodiment, the device can select a pad 4 of appropriate size and a bolt 2 of appropriate length according to the type and size of the cross-section, so it can be used to reinforce the ends of cold-bent steel pressure-bearing specimens of different types and cross-sections.

[0029] In this embodiment, the reinforcement frame 1 of the device is made of welded cast iron, and blue paint is sprayed on the surface of the reinforcement frame 1 to ensure the surface flatness of the frame and prevent rust.

[0030] In this embodiment, the support pad 4 of the device is cut from an aluminum block, which reduces the weight of the device itself and facilitates the support bolt 2 to slightly sink into the support pad 4, providing more effective support for the support pad 4.

[0031] When the device of this embodiment is used to reinforce the end of the specimen in the cold-bent steel pressure test, firstly, according to the cross-sectional type and cross-sectional size of the pressure specimen, a suitable support pad and a support bolt of a suitable length are selected, and then the support bolt is passed through the slot of the reinforcement frame and against the support pad, and at the same time, a locking nut is used to fix the bolt on both the inner and outer sides of the reinforcement frame, and the bolt is slightly embedded in the support pad. When the end of the specimen is deformed under pressure, the support pad can effectively prevent the deformation of the end of the specimen, thereby achieving the purpose of reinforcing and protecting the end of the specimen.

[0032] When the above device of this embodiment is used, the following steps are performed:

[0033] (1) Place the C-section cold-formed steel pressure-bearing test piece 7 on the end plate, and place a 2-3 mm thick acrylic plate close to the cold-formed steel pressure-bearing test piece 7;

[0034] (2) Use the two parts of the reinforcement frame to enclose the C-section cold-formed steel pressure-bearing test piece inside the reinforcement frame, and at the same time, place the support pads 4 of appropriate size close to each surface of the test piece 7 on the acrylic plate, ensuring that the bottom surface of the reinforcement frame 1 and the support pads 4 is slightly higher than the bottom surface of the test piece 7 by 2 to 3 mm;

[0035] (3) First, screw a locking nut 3 onto the supporting bolt 2;

[0036] (4) Insert the support bolt 2 with a locking nut 3 through the slot and blind hole on the reinforcement frame 1;

[0037] (5) Then, respectively, rotate a locking nut 3 from the inner side of the reinforcement frame 1 onto the support bolt 2, ensuring that each support bolt 2 has a locking nut 3 on both the inner and outer sides of the reinforcement frame;

[0038] (6) Control the outer locking nut 3 to remain stationary, and at the same time, adjust the relative support bolt 2 on the reinforcement frame 1 so that the relative support bolt rests against the support pad;

[0039] (7) After all the support bolts 2 are slightly against the support pad 4, further tighten all the support bolts 2 so that all the bolts are slightly sunk into the support pad 4;

[0040] (8) Tighten the locking nuts inside and outside the reinforcement frame 1 and fix the support bolts 2 on the reinforcement frame so that they can effectively provide lateral support force to the support pads;

[0041] (9) Invert the C-section cold-formed steel pressure-bearing specimen 7 and reinforce the other end of the specimen 7 using the same method as above;

[0042] (10) Check the working condition of the support bolts 2 and the locking nuts 3 to confirm that the reinforcement is completed.

[0043] The above-mentioned device of this embodiment is in close contact with the cold-bent steel pressure specimen through the support pad; the support bolts locked on the reinforcement frame by the locking nuts are tightly against the support pad. When the end of the specimen is deformed, the support bolts can provide lateral support force to the support pad, limit the displacement of the support pad, thereby limiting the deformation of the end of the specimen and protecting the end of the specimen from premature damage. At the same time, the size of the support pad, the length of the support bolt and the support position can be reasonably selected according to the type and size of the cross-section, so that the device is not only suitable for the reinforcement of C-section cold-bent steel pressure specimens, but also suitable for the end reinforcement of U-shaped, H-shaped and square-shaped cold-bent steel pressure specimens. The whole device has a clear principle, is simple to make, and is easy to use. It can effectively reinforce the ends of cold-bent steel pressure specimens to prevent premature end damage, and can be used in civil engineering teaching and scientific research experiments.

[0044] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and one or more of the above embodiments are combined into one embodiment. Those skilled in the art can make various changes or modifications or combinations within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other at will.

Claims

1. An end reinforcement teaching aid for cold-bent steel specimen compression test, characterized in that , including: two reinforcement frames, which are respectively arranged at the upper end and the lower end of the cold-formed steel specimen, the reinforcement frames include a first reinforcement frame and a second reinforcement frame, the first reinforcement frame and the second reinforcement frame are U-shaped, and the first reinforcement frame and the second reinforcement frame are rectangular after splicing, the plane where the reinforcement frame is located is perpendicular to the axis of the cold-formed steel specimen, and the reinforcement frame has a plurality of penetrating support bolts in an array around the side, the support bolts tighten the support pads to the surface of the cold-formed steel specimen, and the support bolts are tightly connected to the reinforcement frame through two locking nuts.

2. The end reinforcement teaching aid for cold-bent steel specimen compression test according to claim 1, characterized in that: The reinforcement frame is provided with strip-shaped slots on the circumferential side, and the hole height of the slots is the same as the diameter of the support bolts, providing lateral sliding space for the support bolts passing through the slots to adapt to the reinforcement requirements of cross-sections of different sizes, while limiting the support bolts in the vertical direction.

3. The end reinforcement teaching aid for cold-bent steel specimen compression test according to claim 2, characterized in that: Both ends of the first reinforcement frame and the second reinforcement frame are step structures, and the first reinforcement frame and the second reinforcement frame are overlapped by the step structures. A penetrating blind hole is also provided at the overlap, and the blind hole is used for the support bolt to pass through.

4. The end reinforcement teaching aid for cold-bent steel specimen compression test according to claim 3, characterized in that: The support bolts include transverse support bolts and longitudinal support bolts. The transverse support bolts are arranged in the slot holes on the short sides of the reinforcement frame, and the longitudinal support bolts are arranged in the slot holes and the blind holes on the short sides of the reinforcement frame.

5. The end reinforcement teaching aid for cold-bent steel specimen compression test according to claim 4, characterized in that: The transverse support bolt and the longitudinal support bolt pass through the slotted hole or the blind hole and abut against the support pad, and provide horizontal support force for the support pad.

6. The end reinforcement teaching aid for cold-bent steel specimen compression test according to claim 5, characterized in that: The size of the support pad matches the cross section of the cold-bent steel specimen.

7. The end reinforcement teaching aid for cold-bent steel specimen compression test according to claim 6, characterized in that: The hardness of the support bolt is greater than that of the support pad, and the front end of the support bolt can be embedded in the surface of the support pad and the support pad can maintain a working state.

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