Material Instabilities in Elastic and Plastic Solids: The Perturbative Approach

摘要

The perturbative approach to material instabilities introduced by Bigoni and Capuani [2],[3] (in which a perturbing agent is superimposed to a uniformly stressed and strained infinite medium) is reviewed and applied to show how randomly-distributed dislocation-like defects can induce strain patterns in ductile metallic materials, prestressed near the border of ellipticity loss. These patterns result to be strongly focussed and organized into shear bands, evidencing a well-defined texture in the material.