Research Of Wave Shaping Problem Based On SHB Device

In the field of aerospace,automotive industry,shipbuilding industry and other military or civilian areas,engineering materials will meet impact load such as explosion shock,high-speed collision loading.But the traditional material mechanics experiment was conducted under quasi-static conditions,the stress-strain curve of the materials can not be obtained under high strain rate.So we need to develop a set of efficient and precise testing equipment to determine the material constitutive relation under high strain rate.In 1949,Kolsky invented the split Hopkinson pressure bar.It has been widely seen as an effective method of testing a variety of material mechanical performance under high strain rate by using the experimental apparatus.And for some soft materials and brittle materials such as concrete,rock,ceramics,polymers,we need to use wave shaping technology to get accurate effective experimental data.Numerical simulation has been used in this paper to research the wave shaping technology of Hopkinson bar.And different wave shaping method for dynamic mechanical properties test of material has been discussed.This paper research content is as follows:1.Experiment principles of the Hopkinson bar experiment device and dynamic test method were briefly introduced in this paper.And the research of wave shaping method for the Hopkinson bar device by domestic and foreign scholars has been summarized,the basic theory of the collision impact model,experimental methods are also reviewed in this paper.2.Stress wave theory briefly introduced in this paper.The basic principle of Hopkinson bar is based on one-dimensional stress wave theory.Using the theory of stress wave to explain the dispersion effect of stress wave propagation is caused by transverse inertia.The necessity of the stress wave shaping technology was illuminated.3.Using numerical simulation,the wave shaping technology based on Hopkinson pressure bar apparatus was studied.Two kinds of wave shaping method analyzed in this paper,the simulated sample method and using copper materials as the wave shaper.Then using spherical wave shaper and the method of round head bullet impact the incident bar were presented,improved on the original wave shaping technology.4.Using numerical simulation,the wave shaping technology based on Hopkinson tension bar apparatus was studied.The main factors influencing the incident wave ofHopkinson tesion bar device was studied.Put the metal rod as wave shaper to get the ideal waveform.Then the Hopkinson tesion device was improved by using the method of sleeve bullets.