Numerical Verification of Methods for Avoiding Frictional Effect of Tool-Specimen
Interface and Obtaining Uniaxial Stress-Strain Curve by Impact Compression

— Study of Standardization of Impact Compression Test by Split Hopkinson
Pressure Bar Technique with the Aid of Numerical Simulation 2 —

Abstract

A numerical simulation of the split Hopkinson pressure bar impact compression test is performed to verify the experimental technique for obtaining a more accurate stress-strain curve. The extrapolation method of eliminating the frictional effect of the tool-specimen interface from the stress-strain curve is numerically verified when the curve including oscillatory wave is appropriately smoothed. Furthermore, regarding the technique where the round headed striker bar is used to suppress oscillation in stress waves, the proper test condition is numerically inspected. One appropriate method in determining the radius is presented, where the maximum strain obtained from the dimension of the specimen is conformed with that calculated from the stress pulse. In the case where the reflected wave contains oscillatory components, if strain-rate is calculated from the difference between the input pulse and the transmitted pulse, a more accurate relationship between stress and strain is obtained in a small-strain region.