Dynamic pulling / pressing-twisting device for Hopkinson bar

Abstract

The utility model discloses a dynamic pulling / pressing-twisting device for a Hopkinson bar. The dynamic pulling / pressing-twisting device comprises a spiral base and a spiral column, wherein the lead angle of the device is larger than the friction angle and smaller than 90 degrees, and different lead angles correspond to different pull / press-torsion ratios. In the using process of the device, the spiral base and the spiral column need to be assembled together and placed between the incident rod and the sample, and the incident rod, the pulling / pressing-twisting device, the sample and the transmission rod need to be firmly connected. The dynamic pulling / pressing-twisting device provided by the utility model can be used for carrying out a pulling / pressing and twisting combined mechanical response test on a material, is relatively simple, and only needs to be improved on the basis of an existing Hopkinson bar. Therefore, the device is beneficial for experimenters to quickly master the use method of the device, effectively reduces the mechanical property test cost of the material in a complex stress state, and has remarkable economic benefits and social benefits.

Description

Technical Field

[0001] The utility model relates to the field of material mechanical property testing, in particular to a dynamic tension / compression-torsion device for a Hopkinson bar. Background Art

[0002] In actual engineering, materials are often in complex stress states, such as a combination of shear stress and compression or tensile stress. Therefore, it is necessary to obtain the mechanical properties of materials under complex stress states through experimental means.

[0003] At present, the traditional Hopkinson bar is mostly used to obtain the dynamic mechanical properties of materials under unidirectional compression or tension. In order to achieve composite loading on the traditional Hopkinson bar, the Hopkinson bar needs to be modified, that is, the notched pin is destroyed, the adhesive is destroyed, or the high-strength steel wire is scratched while firing the bullet to suddenly release the torque to generate shear waves. In order to ensure that the two stress waves generated by the two separate transmitters reach the sample at the same time, it is necessary not only to accurately control the generation time of the stress wave, but also to accurately eliminate the time difference caused by the wave velocity difference (the elastic longitudinal wave velocity is about twice the elastic torsion wave velocity). However, the control accuracy of the time by the above-mentioned traditional launch method is in the millisecond level, which is equivalent to the entire loading time of the dynamic experiment, so it is difficult to achieve synchronous loading. In addition, the electromagnetically loaded Hopkinson bar can achieve the synchronization of composite loading, but the equipment is relatively complex and expensive, and it is difficult to promote and apply on a large scale. Summary of the invention

[0004] The utility model aims to overcome the shortcomings of the prior art and provide a dynamic tension / compression-torsion device for a Hopkinson bar. The tension / compression-torsion device is relatively simple and can decompose the tension / compression stress wave into the tension / compression-torsion stress wave by simply improving the existing Hopkinson bar, so that the sample is subjected to a combination of tension / compression and torsion loading at the same time.

[0005] The utility model solves the above technical problems through a technical solution: a dynamic tension / compression-torsion device for a Hopkinson bar is composed of a spiral base and a spiral column, wherein the spiral angle is greater than the friction angle and less than 90°, and different spiral angles correspond to different tension / compression-torsion ratios; an air hole is provided on the side of the spiral base, and air can be quickly inhaled or discharged when the spiral base slides relative to the spiral column; the spiral base and the spiral column need to be assembled together and placed between the incident bar and the sample, and the incident bar, the tension / compression-torsion device, the sample and the transmission bar need to be firmly connected to ensure that the tension / compression-torsion device decomposes the tension / compression stress wave into the tension / compression-torsion stress wave, so that the sample can be subjected to a combined load of tension / compression and torsion at the same time.

[0006] A preferred solution of the utility model is characterized in that the cross-sectional shape of the spiral column of the tension / compression-torsion device is a triangle, a quadrilateral, a pentagon, a hexagon or an ellipse.

[0007] A preferred solution of the utility model is characterized in that the material of the tension / compression-torsion device is a metal that is not easily deformed, such as high-strength aluminum alloy, high manganese steel and stainless steel.

[0008] A preferred embodiment of the present invention is characterized in that the helix angle of the tension / compression-torsion device is 50°, 55°, 60°, 65°, 70° and 75°, and the corresponding tension / compression-torsion ratios are 0.75, 0.64, 0.6, 0.53, 0.44 and 0.35.

[0009] A preferred solution of the utility model is characterized in that the connection between the incident rod, the tension / compression-torsion device, the sample and the transmission rod can be made by gluing with epoxy resin or by mechanical assembly.

[0010] A preferred solution of the utility model is characterized in that the contact surface between the spiral base and the spiral column should be as smooth as possible, and lubricating materials such as lubricating oil, graphite, etc. need to be applied to the contact surface during the experiment to reduce the influence of friction.

[0011] A preferred solution of the utility model is characterized in that the tension / compression-torsion device can also be applied to quasi-static tension / compression experiments, light gas gun experiments and drop hammer experiments.

[0012] The working principle of a dynamic tension / compression-torsion device for a Hopkinson bar provided by the utility model is: torsion is generated by relative movement of a spiral base and a spiral column in the tension / compression-torsion device, and the tension / compression stress wave transmitted from the incident bar is simultaneously decomposed into a tension / compression stress wave and a torsion stress wave, and the converted tension / compression-torsion stress wave acts on a sample at the same time, thereby realizing tension / compression-torsion composite loading on the sample.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] 1. The utility model provides a dynamic tension / compression-torsion device for a Hopkinson bar, which can simultaneously decompose a tension / compression stress wave into a tension / compression stress wave and a torsional stress wave, thereby realizing tension / compression-torsion composite loading on a specimen.

[0015] 2. The dynamic tension / compression-torsion device for a Hopkinson bar provided by the utility model can be manufactured into devices with different helical angles according to experimental needs, thereby changing the ratio of the tension / compression load to the torsion load.

[0016] 3. The dynamic tension / compression-torsion device for the Hopkinson bar provided by the utility model can be improved on the basis of the traditional Hopkinson bar to realize tension / compression-torsion composite loading of the sample, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a specific implementation of the dynamic compression-torsion device for a Hopkinson bar of the utility model.

[0018] Figure 2 It is a schematic diagram of a specific implementation of the dynamic stretching-torsion device for a Hopkinson bar of the utility model. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0020] See also Figure 1 and Figure 2 A dynamic tension / compression-torsion device 7 for a Hopkinson bar of the utility model comprises a spiral base 3 and a spiral column 4, wherein the spiral angle is greater than the friction angle and less than 90°, and different spiral angles correspond to different tension / compression-torsion ratios; the spiral base 3 is provided with air holes on its side, and air can be quickly inhaled or discharged when it slides relative to the spiral column 4; the spiral base 3 and the spiral column 4 need to be assembled together and placed between the incident rod 5 and the sample 2, and the incident rod 5, the tension / compression-torsion device 7, the sample 2 and the transmission rod 1 need to be firmly connected to ensure that the tension / compression-torsion device 7 decomposes the tension / compression stress wave into the tension / compression-torsion stress wave, so that the sample 2 can be subjected to the combined loading of tension / compression and torsion at the same time.

[0021] The cross-sectional shape of the spiral column of the tension / compression-torsion device 7 is a quadrilateral.

[0022] The material of the tension / compression-torsion device 7 is high-strength aluminum alloy.

[0023] The helix angle of the tension / compression-torsion device 7 is 65°, and the corresponding tension / compression-torsion ratio is 0.53.

[0024] The connection between the incident rod 5, the tension / compression-torsion device 7, the sample 2 and the transmission rod 1 is bonded by epoxy resin.

[0025] The contact surface between the spiral base 3 and the spiral column 4 should be as smooth as possible, and graphite needs to be applied to the contact surface during the experiment.

[0026] See also Figure 1 and Figure 2The working principle of a dynamic tension / compression-torsion device for a Hopkinson bar of the utility model is further described below in conjunction with the accompanying drawings:

[0027] The spiral base 3 and the spiral column 4 in the tension / compression-torsion device 7 of the utility model move relative to each other to generate torsion, and the tension / compression stress wave transmitted from the incident rod 5 is simultaneously decomposed into a tension / compression stress wave and a torsion stress wave, and the converted tension / compression-torsion stress wave acts on the sample 2 simultaneously, thereby realizing tension / compression-torsion composite loading on the sample 2.

[0028] The above is a preferred implementation mode of the present invention, but the implementation mode of the present invention is not limited by the above content. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A dynamic tension / compression-torsion device for a Hopkinson bar, characterized in that: The device consists of a spiral base and a spiral column. The spiral angle is greater than the friction angle and less than 90°. Different spiral angles correspond to different tension / compression-torsion ratios. The spiral base is provided with air holes on the side, which can quickly inhale or exhaust air when it slides relative to the spiral column. The spiral base and the spiral column need to be assembled together and placed between the incident rod and the sample. The incident rod, the tension / compression-torsion device, the sample and the transmission rod need to be firmly connected to ensure that the tension / compression-torsion device decomposes the tension / compression stress wave into the tension / compression-torsion stress wave, so that the sample can be subjected to the combined loading of tension / compression and torsion at the same time.

2. A dynamic tension / compression-torsion device for a Hopkinson bar according to claim 1, characterized in that: The cross-sectional shape of the spiral column of the tension / compression-torsion device is a triangle, a quadrilateral, a pentagon, a hexagon and an ellipse.

3. A dynamic tension / compression-torsion device for a Hopkinson bar according to claim 1, characterized in that: The material of the tension / compression-torsion device is metal which is not easy to deform.

4. A dynamic tension / compression-torsion device for a Hopkinson bar according to claim 1, characterized in that: The helix angles of the tension / compression-torsion device are 50°, 55°, 60°, 65°, 70° and 75°, and the corresponding tension / compression-torsion ratios are 0.75, 0.64, 0.6, 0.53, 0.44 and 0.

35.

5. A dynamic tension / compression-torsion device for a Hopkinson bar according to claim 1, characterized in that: The connection between the incident rod, the tension / compression-torsion device, the sample and the transmission rod can be made by gluing with epoxy resin or by mechanical assembly.

6. A dynamic tension / compression-torsion device for a Hopkinson bar according to claim 1, characterized in that: The contact surface between the spiral base and the spiral column should be as smooth as possible, and lubricating material needs to be applied to the contact surface during the experiment.

7. A dynamic tension / compression-torsion device for a Hopkinson bar according to claim 1, characterized in that: The tension / compression-torsion device can also be applied to quasi-static tension / compression experiments, light gas gun experiments, and drop hammer experiments.

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