Bolt connection pair uniform loading test device

Abstract

The utility model discloses a uniform loading test device for bolt connection pairs, which relates to the field of bolt fatigue loading tests and comprises a special-shaped loading steel plate, a plurality of first test screw holes distributed along an arc are arranged on the special-shaped loading steel plate, and a bolt connection pair is arranged at each test screw hole; an upper fixing steel plate and a lower fixing steel plate are arranged on the upper side and the lower side of the loading steel plate respectively, and second test screw holes corresponding to the first test screw holes are formed in the upper fixing steel plate and the lower fixing steel plate respectively; the bolt connecting pair sequentially penetrates through the upper fixing steel plate, the test screw hole and the lower fixing steel plate to be connected and fixed; the special-shaped loading steel plate is matched with the multiple first test screw holes distributed in the arc shape, all bolt connection pairs can be evenly loaded through different loading angles and loading distances on the special-shaped loading steel plate, the problem that loads cannot be evenly distributed in the fatigue loading process of the bolt connection pairs is solved, and the test efficiency and precision are effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of bolt fatigue loading test, in particular to a bolt connection pair uniform loading test device. Background Art

[0002] When rail transit crosses over a city, steel truss bridges are often used to save construction time. When a train runs across a steel truss bridge, the reciprocating vibration will generate fatigue loads on the bolted nodes of the steel truss bridge, causing the clamping force of the bolted connection to loosen. Over time, this may even cause the bolts to fall off, causing the stiffness and strength of the steel truss bridge to decrease, seriously endangering the safety and durability of rail transit operations. Therefore, it is necessary to establish the relationship between the residual clamping force and the residual fatigue life of the bolted connection through model tests, so as to predict the residual fatigue life of the bolted connection.

[0003] In the existing bolt connection model test, the bolt connection pairs are arranged in a straight line, which leads to uneven stress on the bolt connection pairs under the same fatigue load and low accuracy of the test results. Utility Model Content

[0004] In view of the deficiencies in the above-mentioned prior art, the utility model provides a uniform loading test device for bolted connections, which solves the problem that the load cannot be evenly distributed during fatigue loading of bolted connections, and can effectively improve the test efficiency and accuracy.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A uniform loading test device for bolt connection pairs comprises a special-shaped loading steel plate, on which a plurality of first test screw holes distributed along an arc are provided, and a bolt connection pair is arranged at each test screw hole; an upper fixed steel plate and a lower fixed steel plate are respectively arranged on the upper and lower sides of the loading steel plate, and second test screw holes corresponding to the first test screw holes are respectively arranged on the upper fixed steel plate and the lower fixed steel plate; the bolt connection pair passes through the upper fixed steel plate, the test screw holes and the lower fixed steel plate in sequence for connection and fixation.

[0007] Preferably, the plurality of first test screw holes are distributed axially symmetrically to ensure that the bolt connections on both sides are subjected to uniform stress.

[0008] Preferably, the bolt connection pair includes a screw rod and a nut to ensure connection strength.

[0009] Preferably, the bolt connection pair also includes a gasket, which is arranged between the nut and the test screw hole to ensure that the bolt is tightened and stressed.

[0010] Preferably, the special-shaped loading steel plate is a combination of an isosceles trapezoid and an arc shape, the two ends of the arc shape are connected to the two ends of the long side of the isosceles trapezoid, the fatigue load is applied to the short side of the isosceles trapezoid, and the test screw holes are evenly distributed along the edge of the arc shape to achieve uniform load distribution of each bolt connection during fatigue loading.

[0011] Preferably, the arc angle is 120°.

[0012] Preferably, the length of the long side of the isosceles trapezoid is √3 times the diameter of the arc; the height of the isosceles trapezoid is equal to the radius of the arc; the short side of the isosceles trapezoid is 0.6 times the long side, thereby ensuring that all bolt connection pairs are evenly stressed during fatigue loading.

[0013] Preferably, the special-shaped loading steel plate is processed as one piece to ensure that the fatigue load is stably transferred to each pair of bolt connections during the loading process.

[0014] Preferably, a plurality of fixing bolt holes are evenly arranged on the upper fixing steel plate and the lower fixing steel plate, respectively, and the fixing bolt holes cooperate with the fixing bolts to fix the upper fixing steel plate and the lower fixing steel plate together.

[0015] Preferably, the bottom end of the fixing bolt is anchored on the test bench.

[0016] Preferably, it also includes a fatigue testing machine, which is arranged on a side of the special-shaped loading steel plate away from the test screw hole.

[0017] Preferably, the second test screw hole is arranged in the middle position of the upper fixed steel plate and the lower fixed steel plate, and the two sides of the upper fixed steel plate are symmetrical about the special-shaped loading steel plate to ensure the stability of the upper and lower fixed steel plates when the load is applied.

[0018] By adopting the above technical solution, the beneficial effects of the utility model are as follows:

[0019] The utility model cooperates the special-shaped loading steel plate with a plurality of first test screw holes distributed in an arc shape, and can make each bolt connection pair evenly loaded through different loading angles and loading distances on the special-shaped loading steel plate, thereby solving the problem that the load cannot be evenly distributed during fatigue loading of the bolt connection pair, and effectively improving the test efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0021] Figure 1 This is the main view of the overall structure of the utility model;

[0022] Figure 2 This is a top view of the overall structure of the utility model;

[0023] Figure 3 This is a top view of the special-shaped loading steel plate of the utility model;

[0024] Figure 4 This is a top view of the upper fixed steel plate of the utility model;

[0025] Figure 5 This is the main view of the bolt connection pair of the utility model;

[0026] Figure 6 This is the front view of the fixing bolt of the utility model.

[0027] In the figure: 1. Bolt connection pair; 11. Screw; 12. Nut; 13. Washer; 2. Special-shaped loading steel plate; 21. First test screw hole; 3. Upper fixing steel plate; 31. Second test screw hole; 32. Fixing bolt hole; 4. Lower fixing steel plate; 5. Fixing bolt. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0030] Embodiment 1

[0031] In a typical embodiment of the present application, a bolt connection uniform loading test device is provided, such as Figure 1-6 As shown, it includes a special-shaped loading steel plate 2, on which a plurality of first test screw holes 21 distributed along an arc are provided, and a pair of bolt connection pairs 1 are arranged at each test screw hole; an upper fixed steel plate 3 and a lower fixed steel plate 4 are respectively arranged on the upper and lower sides of the special-shaped loading steel plate 2, and second test screw holes 31 corresponding to the first test screw holes are respectively arranged on the upper fixed steel plate 3 and the lower fixed steel plate 4; the bolt connection pair 1 passes through the upper fixed steel, the special-shaped loading steel plate 2 and the lower fixed steel plate 4 in sequence for connection and fixing.

[0032] Specifically, Figure 2 As shown, the plurality of first test screw holes 21 are distributed axially symmetrically to ensure that the bolt connection pairs on both sides are subjected to uniform force.

[0033] In this embodiment, the bolt connection pair 1 includes a screw rod 11 and a nut 12 to ensure the connection strength. Figure 5 As shown, the bolt connection pair further includes a gasket 13, which is arranged between the nut 12 and the second test screw hole 31 to ensure that the bolt is tightened and stressed.

[0034] like Figure 2 , 3 As shown, in this embodiment, the shape of the special-shaped loading steel plate is set to a combination of an isosceles trapezoid and an arc shape, wherein the two ends of the arc shape are connected to the two ends of the long side of the isosceles trapezoid, the fatigue load is applied to the short side of the isosceles trapezoid, and the test screw holes are evenly distributed along the edge of the arc shape. In this way, when the fatigue load is applied, different bolt connection pairs can achieve uniform load distribution in each bolt connection pair through different loading angles and loading distances relative to the loading position.

[0035] Specifically, in the combined-shaped special-shaped loaded steel plate, the arc angle is 120°, the length of the long side of the isosceles trapezoid is √3 times the diameter of the arc; the height of the isosceles trapezoid is equal to the radius of the arc; the short side of the isosceles trapezoid is 0.6 times the long side, so that all bolt connection pairs are evenly stressed during fatigue loading.

[0036] In this embodiment, the special-shaped loading steel plate is processed as one piece, ensuring that the fatigue load can be stably transmitted to each pair of bolt connections during the loading process.

[0037] like Figure 4 As shown, four fixing bolt holes 32 are respectively provided on the upper fixing steel plate 3 and the lower fixing steel plate 4. In this embodiment, the upper fixing steel plate 3 and the lower fixing steel plate 4 are rectangular plates, and the four fixing bolt holes 32 are distributed on the four corners of the rectangular plate, and the fixing bolt holes on the left and right sides are symmetrically distributed to ensure the stability and balance of the connection between the upper and lower fixing steel plates during fatigue loading. In this embodiment, the fixing bolts 5 are used to cooperate with the fixing bolt holes 32 to fix the upper fixing steel plate and the lower fixing steel plate.

[0038] In addition, the present embodiment also includes a fatigue testing machine, which is arranged on the side of the special-shaped loading steel plate away from the test screw hole. During the test, the bottom end of the fixing bolt is anchored on the test bench, and the fatigue testing machine is started to load the special-shaped loading steel plate. The special-shaped loading steel plate evenly transfers the fatigue load to each bolt connection pair through different angles and distances, thereby improving the accuracy of the test results.

[0039] like Figure 4As shown, in this embodiment, the second test screw hole 31 is arranged in the middle position of the upper fixed steel plate and the lower fixed steel plate, and the two sides of the upper fixed steel plate are symmetrical about the special-shaped loading steel plate to ensure the stability of the upper and lower fixed steel plates when fatigue load is applied.

[0040] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Those skilled in the art should understand that the utility model can be modified and varied in various ways. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A bolt connection uniform loading test device, characterized in that It comprises a special-shaped loading steel plate, on which a plurality of first test screw holes distributed along an arc are arranged, and a bolt connection pair is arranged at each test screw hole; an upper fixed steel plate and a lower fixed steel plate are arranged on the upper and lower sides of the special-shaped loading steel plate respectively, and second test screw holes corresponding to the first test screw holes are arranged on the upper fixed steel plate and the lower fixed steel plate respectively; the bolt connection pair passes through the upper fixed steel plate, the special-shaped loading steel plate and the lower fixed steel plate in sequence for connection and fixing.

2. A bolt connection uniform loading test device as claimed in claim 1, characterized in that: The plurality of first test screw holes are distributed in an axisymmetric manner.

3. A bolt connection uniform loading test device as claimed in claim 1, characterized in that: The bolt connection pair includes a screw rod and a nut.

4. A bolt connection uniform loading test device as claimed in claim 3, characterized in that: The bolt connection pair also includes a gasket, which is arranged between the nut and the test screw hole.

5. A bolt connection uniform loading test device as claimed in claim 1, characterized in that: The special-shaped loading steel plate is a combination of an isosceles trapezoid and an arc shape, the two ends of the arc shape are connected to the two ends of the long side of the isosceles trapezoid, the fatigue load is applied to the short side of the isosceles trapezoid, and the test screw holes are evenly distributed along the edge of the arc shape.

6. A bolt connection uniform loading test device as claimed in claim 5, characterized in that: The arc angle is 120; the length of the long side of the isosceles trapezoid is √3 times the diameter of the arc; the height of the isosceles trapezoid is equal to the radius of the arc; the short side of the isosceles trapezoid is 0.6 times the long side.

7. A bolt connection uniform loading test device as claimed in claim 5, characterized in that: The special-shaped loading steel plate is processed in one piece.

8. A bolt connection uniform loading test device as claimed in claim 1, characterized in that: The upper fixing steel plate and the lower fixing steel plate are respectively and evenly provided with a plurality of fixing bolt holes, and the fixing bolt holes cooperate with the fixing bolts to fix the upper fixing steel plate and the lower fixing steel plate together.

9. A bolt connection uniform loading test device as claimed in claim 8, characterized in that: The bottom end of the fixing bolt is anchored on the test bench.

10. A bolt connection uniform loading test device as claimed in claim 1, characterized in that ,, also includes a fatigue testing machine, which is arranged on a side of the special-shaped loading steel plate away from the test screw hole.

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