Simulating Wave Propagation in SHPB with Peridynamics

Abstract

Split Hopkinson’s pressure bar (SHPB) is commonly used for characterizing materials at high strain rates. In obtaining an admissible stress–strain curve at a specific strain rate, force equilibrium through the specimen is required. Due to the blunt collision between the striker bar and the incidence bar in SHPB, a strain wave with a blunt wave front is usually obtained in SHPB test. Unfortunately, the blunt wave front can damage the specimen prematurely, resulting in an inconclusive test. Hence, a gradual loading ramp, such as that commonly practiced in quasi-static characterizations is preferred. In order to achieve a gradual loading fashion, a shaper made of a softer material should be placed in between the striker bar and the incidence bar. The selection of the shaper material and its dimension and thickness, however, is not trivial. Numerous trial-and-errors are usually required. This study presents the simulation of wave propagation in SHPB based on peridynamics. In addition to striker bar, incidence bar and transmission bar, the one-dimensional peridynamic simulation can also accommodate a shaper. Hence, it can be used for shaper design.