Abstract
Propagation velocities of the incremental torsional wave were measured on commercial pure aluminum and copper specimens through the experiments in which incremental torsional impacts were applied to the tubular specimens pre-stressed torsionally to various plastic ranges. It became clear by these experimental results that, for both materials, the incremental wave velocity coincided with the elastic torsional wave velocity, and so the component of the instantaneous plastic response did not appear in the stress levels attained to by usual techniques.
A constitutive equation was proposed, which can describe not only a boundary limit of the region where the plastic deformation is caused mainly by the movement of dislocations, but also various material behaviors in a wide range of strain rates.
