ABSTRACT
For testing rocks in a split Hopkinson pressure bar (SHPB), an optimally sized pulse shaper (PS) is needed to filter out high-frequency oscillations and achieve a half-sine wave-type incident pulse. The present work performs pulse-shaped experiments on Kota sandstone in a large-diameter (76 mm) SHPB at strain rates up to 362/s. Disc-shaped copper is used as a PS. PS diameter is varied, and its effects on the incident rise time are investigated. It is found that using an appropriate diameter facilitates dynamic force equilibrium. When the diameter increases from 15 mm to 20 or 25 mm, it does not significantly improve the incident pulse rise time. Several oscillations are observed in the rising portion of the incident pulse when the PS diameter equals 25 mm.
