Mesomechanics of Porous Materials Under Intense Dynamic Loading

Abstract

Intense dynamic loading of porous, granular materials results in a completely new class of phenomena, in comparison with their behavior considered in the previous chapter. It includes a complex geometry of plastic flow, as well as fracture and melting. The mechanical deformation (shock loading, plastic flow) of heterogeneous porous materials has an essentially multiscale nature. For example, the hierarchy of scales includes: Macroscales. Length of shock impulse, typical length of deformable part of the material. Mesoscales. Shock front thickness, shear band thickness, sizes of the particles and pores, sizes of fragmented material, size of plastic flow localized on the interfaces of particles, plastic flow around pores, spacing between shear bands, heat conductivity, and mass diffusion lengths. Very often this scale is close to the initial scale of material heterogeneity that makes the continuum approach problematic. Microscales. Sizes of lattice defects (dislocations, point defects, twins), possible additional scales parameters reflecting the nonlinear interaction, and collective dynamic behavior in molecular systems.