On Evolutional and Catastrophic Regimes of Meso-Macro Energy Exchange in Dynamically Loaded Media

摘要

Study of the role of velocity fluctuations in processes of energy exchange between mesoscopic and macroscopic scale levels represents an important stage in the development of our knowledge about the shock-wave behavior of heterogeneous materials. In the case of dynamic deformation, the concept of mesoparticle has much wider meaning as applied to quasistatic processes, in which mesoparticles are specific structural defects such as dislocation groups, vortex structures, shear bends, and other structural formations of scale 0.1-10 μm [1]; they represent field structures, the only distinct feature of which is the presence of a velocity-correlated group of medium points. This means that a mesoparticle is a space formation, the internal points of which have identical or close velocities. The lifetime of these structures is determined by the duration of the dynamic deformation process. Each mesoparticle, as a separate structural formation, has its own overall velocity. In a heterogeneous medium, a dynamically deformed structure is characterized by velocity scattering. Therefore, mesoparticle velocity fluctuations can remove a considerable part of momentum and energy transferred to the medium.