A CONTINUUM-MECHANICS THEORY OF MICROSTRUCTURE FORMATION IN DEFORMED SOLIDS

Ductile solids are strongly dissipative, non-linear systems for which instability transitions and selforganization effects are typical. A co nvenient framework for description of these phenomena is provided by A saro et al.'s model of a ductile crystal where densities of stored dis locations are introduced as additional field variables. It is shown th at inelastic properties are governed by two types of instability trans itions. The first leads to selforganization in the form of a deformati on microstructure. The second type causes shear banding and misorienta tion of the crystal lattice which modify microstructure and may initia te rupture processes. The suggested theory indicates that inelastic pr operties of ductile solids are consequences of a competition between t hese instability processes.