Plastic waves in a rate sensitive material—I. Waves of uniaxial stress

Abstract

Summary Experiments have been carried out in which longitudinal plastic waves have been propagated in thin-walled tubes of alpha-titanium. Strain-time profiles recorded in these experiments show evidence of (i) stress levels considerably above quasi-static values at the same strain, (ii) decay of the amplitude of the elastic precursor, and (iii) variation with distance of propagation of the speed at which a given level of strain propagates. These features of the strain-time profiles are interpreted as indicating that a strain-rate dependent theory is necessary to describe the observed wave phenomena. Numerical solutions based on such a theory agree reasonably well with experimental results. For these solutions a plastic strain-rate function is used which agrees with data from quasi-static and split Hopkinson bar tests on the same tubes.