Material Response and Continuum Relations; or From Microscales to Macroscales

Abstract

Brief qualitative assessments are presented of a few approaches to macroscopic stress-strain relations for structural metals, alloys, and composites and some remarks are made about fracture. Ignoring the scale and applying continuum mechanics to the microstructure lies at one extreme, the dislocation scale treatment of single crystals and simple polycrystals at another. When, as for structural aluminum alloys, the shear stress required for continuing plastic deformation is so much higher than for the constituent single crystals, it seems unlikely that the latter approach is able to exhibit the salient features of macroscopic behavior.