Elastic/Viscoplastic Theory Examined Using Radial Cylindrical Stress Waves

Two distinct types of experiments are employed to examine an elastic/viscoplastic constitutive theory in a radial cylindrical configuration. One examines the plane-strain plastic response of hollow cylinders subjected to an internal finite-rise-time pressure pulse; the other examines the decay behavior of the cylindrical elastic precursor associated with high stress level impact loading. A linear and an exponential form of the viscoplastic strain-rate function are considered. For 1100-0 aluminum, solutions of the associated initial-boundary-value problems show that, of the two forms, only the exponential viscoplastic strain-rate function, based on an activation energy dislocation concept, can satisfy the results of both experiments.