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über das Thema
From the viewpoint of modern mechanics and physics of solids, internal
structure of a material under deformation exerts a predominating influence on
the elastic-plastic behaviour at the meso-scale level. Experimental and
theoretical investigations indicate a key role of internal heterogeneity for the
development of stress concentration and plastic strain localisation under
The majority of the experimental methods of in situ investigations of plastically deformed materials are mostly reduced to surface observations. In this connection, a numerical simulation including consideration of internal structure in an explicit form shows promise for studying plastic deformation patterns in the bulk of heterogeneous media.
In our work we investigate numerically elasto-plastic behaviour of heterogeneous media under dynamic loading. Assuming that a medium under plastic deformation retains its continuity at the meso and macro scale levels, we apply mathematical tools and a numerical method of continuum mechanics. An internal structure is introduced by prescribing appropriate physical properties to computational cells corresponding to different structural elements.
A relaxation approach is applied to describe elasto-plastic behaviour, according to which stresses increase in proportional to total strain rates and relax as plastic deformation develops. A special yield criterion is developed to take into account surface and interface effects. The results of two- and three-dimensional calculations of dynamic deformation, including tension, compression and shock wave loading, are presented and discussed.