High strain rate torsional testing of a high manganese steel: Design and simulation

In this study, some less-discussed aspects of designing a high strain rate torsional testing machine adapted from the Kolsky bar setup are surveyed with an emphasis on the clamping system design. Dynamic torsional experiments with true strain rates in the range of ∼500-1700 /s are conducted on specimens of a high-Mn TRIP/TWIP steel. Deformation characteristics of torsional specimens with different geometries are studied through coupled field thermo-mechanical finite element analyses using ANSYS commercial software package. The effect of specimen geometry on the stress and strain distributions and accuracy of the experimental results is also studied. Using the FEM analysis, deformation temperature rise is attained over the specimen gauge zone and its influence on the stacking fault energy and mechanical behavior of the steel is investigated.