Split Hopkinson Pressure Bar Method with Finite-Length Specimen Utilizing Fourier Analysis
Tadayoshi SHOYAMA and Tadashi SHIOYA
Abstract:Split Hopkinson Pressure Bar (SHPB) is known as a simple method to investigate the deformation of materials at high strain rate. To heat the specimen upto the melting point of the material of elastic bars, the specimen must have a finite length. In such case, the result is inaccurate because of the assumption of existing evaluation method that the specimen has infinitely short length. This paper introduces a new evaluation method utilizing Fourier analysis which enables accurate investigation of viscoelastisity of materials considering the stress and the temperature distribution in a long specimen. By the use of this method, The attenuation of silicon nitride, at high temperature from 900 to 1320 and at high strain rate in frequency around 4kHz, was obtained. Key Words:SHPB, Hopkinson bar, Viscoelastisity, Fourier analysis, FFT, Silicon nitride