Numerical Study on Impact Testing of Low-Strength Materials Using Flanged Split-Hopkinson Bar Method

Abstract

In this study, we investigated the effect of flange part on stress wave propagation in the compression test of low strength material using flanged Split Hopkinson Bar method. Due to the flange with a larger radius than the input/output bar, a pair of reflected waves of compression and tension with apparently different shapes from the one-dimensional reflected wave depending on mechanical impedance mismatch was observed. Depending on the relationship between the elastic wave propagation speed in the input/output bar and the gauge position, the precursive reflected wave of compression corresponds to the rising time of the stress wave, and the tensile reflected wave propagated subsequently corresponds to the falling time. It was found that when the flange is used for impact compression test of low strength material, the effect of the flanges on the reflected wave becomes small. However, it was suggested that the transmitted wave may be affected in the impact compression test of low strength material.