DISLOCATION CONCEPTS OF STRAIN RATE EFFECTS

Whereas von Karman and Taylor independently based their analyses for plastic wave propagation on the deforma tion concept which assumes the deformation stress is exclusively a function of the plastic strain, Malvern believed that a viscoelastic type of behavior is more realistic, assuming the flow stress is a function of the strain rate as well as the strain. It is shown that both concepts are substantiaily correct under appropriate circumstances. This thesis is upheld not only in terms of experimental evidence but also in terms of deductions arrived at from elementary dislocation theory. (auth)