Launcher based on Hopkinson pull rod test equipment

Abstract

The invention designs a launcher according to a principle and requirements of a Hopkinson pull rod test. The launcher mainly comprises a sleeve, a base, a piston, a sliding rail and a supporting base and the like, and is mainly structurally characterized in that high-pressure gas pushes the piston to move so as to push a tubular bullet to speed up, so that the bullet knocks a launching rod at a certain speed; and the thin-wall cylindrical sliding rail is used for supporting movement of the piston and the tubular bullet, thereby achieving a tensile loading way with relatively good reliability and consistency. The launcher is simple and reliable in structure, relatively low in cost, obvious in accelerating effect, thereby ensuring a relatively high bullet speed within a relatively short stroke, and good in test consistency, thereby ensuring a consistent bullet speed under a certain condition; through pressure regulation of the high-pressure gas, different bullet loading speeds can be obtained; and through a design of the sliding rail, the bullet does not contact the launching rod during acceleration, thereby avoiding influence of interaction of the bullet and the launching rod on a test result.

Description

technical field [0001] The invention belongs to the field of material dynamic mechanics research, in particular to a launching device based on Hopkinson pull bar test equipment. Background technique [0002] The separate Hopkinson test device is one of the important methods to study the mechanical properties of materials. Although its principle and technology have been matured, the test device itself is not standardized and needs to be further developed. Among them, the Hopkinson tie rod is a commonly used technical means for the study of dynamic tensile properties of materials. The Hopkinson test is based on a one-dimensional stress wave, and the loading wave generated by the impact must also satisfy the one-dimensional assumption. Therefore, regardless of the compression rod or the tension rod, the impact surface between the bullet and the incident rod should be symmetrical. Due to the particularity of the tension rod loading, the methods adopted by each department are di...

AI Technical Summary

Problems solved by technology

This method has high requirements on the fixture, and is only suitable for materials with a small modulus, and the consistency of the test due to the influence of the fixture is also poor

In the article "Tension and compression tests of two polymers under quasi-static and dynamic loading" (Chen.W, Polymer Testing, 21(2):113-1212002), the tubular bullet is directly placed on the incident rod, and the pressure difference is used to directly compress the tubular bullet. Bullet loading, the pressure difference in this way has a small loading force on the bullet, the required loading section is longer and the interaction between the bullet and the incident rod has a certain impact on the consistency of the test loading

Images