An Analysis of the Split Hopkinson Bar Technique for Strain-Rate-Dependent Material Behavior

Abstract

The analysis of the split Hopkinson bar experiment for determining dynamic material behavior is examined for several specific examples of specimen materials which exhibit strain-rate-dependent mechanical behavior. The torsional mode of deformation is chosen as more closely representing a one-dimensional state of stress. Details of the propagation and reflection of stress waves within the specimen are studied using a numerical procedure based on the method of characteristics. Reconstituted stress-strain curves calculated from the conventional analysis of the split Hopkinson bar experiment are compared with actual material behavior for several simulated experiments involving variations in input stress, gage length, material behavior, and static stress-strain curves including statically prestressed materials. The validity of the experimental technique is discussed and limitations on its use are delineated.