Strength and viscosity of metals in a wide range of strain rate variation

For a large class of problems of high-rate straining of metallic shells driven in one way or another toward the center or axis of symmetry, mathematical modeling of dynamic processes is carried out according to the scheme of nonstationary straining of a compressible viscoplastic medium in a region with free boundaries. The difficulties emerging in this case are due to the absence of reliable experimental data on the behavior of the dynamical yield limit σs and the dynamical viscosity coefficient μ for many metals in a wide range of the strain rates ε > 103 - 106 sec-1. In this paper we suggest a new technique for determining these characteristics of metals with the use of experiments on compressed cylindrical shells