Journal of Theoretical
and Applied Mechanics

14, 1, pp. 95-126, Warsaw 1976

Analiza jednowymiarowych fal uderzeniowych i przyspieszenia w ośrodku niesprężystym

Witold Kosiński
The model of the inelastic (dissipative) continuous media assumed in the paper is described by the strain and by the finite set of additional variables, called the internal state variables or internal parameters. After appropriate specification of internal variables the model may be used to describtion viscoelastic, ageing or elastic-viscoplastic materials. In the paper the waves are understood as some special curves in the phase space X-t, on which the variables describing the behaviour of the medium, or their derivatives, suffer jump discontinuities. The explicit expressions for the change in the amplitudes of acceleration and shock waves are derived. These expressions established the existence of ``critical'' amplitudes. The propositions on the local and global (in time) behaviour of the amplitudes are formulated. The above analysis is applied to the wave propagation in non-linear viscoelastic and elastic-viscoplastic materials.