Tensile Fixture and Experimental Method for Split Hopkinson Tie Bar Thin Specimen

Abstract

The invention discloses a tensile fixture for a split Hopkinson pull rod sheet test piece and an experimental method. The tensile fixture comprises a main fixture body and an auxiliary fixture body; afixed block and a positioning convex block are arranged on the semicircular section of the main fixture body; a positioning clamping groove is formed between the fixing block and the positioning protruding block; a placing groove for placing a test piece is formed in the semicircular section of the main fixture body; a positioning cylinder is arranged in the placing groove; a positioning groove matching the positioning protruding block is formed in the semicircular section of the auxiliary fixture body; a protrusion, at the positioning groove, of the auxiliary fixture body is a positioning clamping block; the positioning clamping block matches the positioning clamping groove; and a positioning blind hole matching the positioning cylinder is formed in the semicircular section of the auxiliary fixture body. According to the invention, the sheet-shaped test piece is effectively prevented from slipping off in the test process, the fastening stability of the fixture and the test piece is ensured, the waveform propagation integrity in the test process is ensured, the interference to stress waves is avoided, and the test data precision is effectively improved.

Description

technical field [0001] The invention relates to the research technical fields of material mechanics, experimental mechanics, etc., in particular to a tensile fixture and an experimental method for a separated Hopkinson tie bar thin-section specimen. Background technique [0002] The research on the dynamic mechanical properties of materials under high strain rate has important academic and engineering value in the fields of aerospace, rail transit, automobile, ship and national defense engineering. Accurately obtaining the mechanical response of materials in a wide strain rate range, especially the mechanical response of materials at medium and high strain rates has become the focus and difficulty of research. At present, the commonly used testing equipment for dynamic mechanical properties of materials mainly includes high-speed material testing machines with servo hydraulic control system (10 0 ~10 3 the s -1 ), drop weight testing machine (10 1 ~10 3 the s -1 ) and ...

AI Technical Summary

Problems solved by technology

[0009] The shortcoming of the prior art 1: For the above-mentioned dynamic tensile test fixture, a complex connection method is adopted, which involves a tapered surface with high processing requirements, and the required main clamp body, clip and threaded fixing fixture are assembled After the completion, there are still relatively many gaps, which will make the fit between the fixtures not tight, interfere with the propagation of the stress wave, and affect the test effect

[0012] The shortcoming of this prior art 2: For the above-mentioned clamping device and experimental method of a separate Hopkinson tie bar specimen, the specimen is clamped and connected by means of physical loading by using a briquetting block and a screw, and there is a joint section Large changes, defects that interfere with stress wave propagation

[0015] The shortcoming of this prior art 3: for above-mentioned a kind of separation type Hopkinson pull rod test fixture, the method for connecting with screw connection between main clamp body and secondary clamp body gets up, but thread fits easily to appear gap, under high strain rate During the tensile test, it is easy to loosen between the main clamp body and the auxiliary clamp body, resulting in signal jitter

[0019] The shortcoming of this prior art 4: for the above-mentioned a kind of detachable dynamic tensile test fixture, although adopt the mode of gluing and thread fixing to ensure that the test piece will not slip off, but the connection method is relatively complicated, and it is difficult for the reinforcement plate. The processing accuracy is high, and there are still many gaps in the threaded fixture after assembly, which interferes with the propagation of stress waves and affects the test results

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