Two dimensional plastic waves in quasi rate independent viscoplastic materials

M. V. Mićunović, C. Albertini, A. Grillo, I. Muha, G. Wittum, L. Kudrjavceva

The subject of this work is an analysis of the experimental biaxial Hopkinson bar technique when such a device consists of a cruciform tensile specimen surrounded by four very long elastic bars. Unlike commonly applied by-pass analysis which attempts to draw conclusions from behaviour of elastic bars we attempt to take into account real plastic waves inside the specimen with few hundreds of reflections. A quasi rate-independent as well as a more general rate-dependent tensor function model for ASME 537 steel are applied. Plastic wave speeds non-existent in traditional elasto-viscoplasticity are analyzed. Some preliminary numerical results for symmetric and non-symmetric loading cases valid for initial and subsequent elastic ranges are given.