|
Results of experimental research on shock loading of solid materials demonstrate
that the revealed dependences of waveforms and threshold of the structure instability on
strain-rate, target thickness and state of the material structure cannot be described in the
framework of the conventional continuum mechanics. New concept of shock-wave processes
in condensed matter is proposed on base of nonlocal theory of nonequilibrium transport which
allowed a transition from the elastic medium reaction to the hydrodynamic one depending on
the rate and duration of the loading. A new mathematical model of elastic-plastic wave is
constructed to describe the elastic precursor relaxation and the plastic front formation taking
into account the changing Ïf material properties during the wave propagation. Analysis of
experimental waveforms shows that for the shock-induced processes it is incorrect a priori to
divide the components of stress and strain into elastic and plastic parts. The model allowed
accounting for the inertial medium properties under short-duration loading and selforganization
of new internal structures.
Keywords: shock waves; elastic precursor; plastic front; velocity variation; velocity defect; nonlocal model; transport processes |
full paper (pdf, 2144 Kb)