Formulation of Material Strength Condition for Endochronic Theory of Non-Elasticity Allowing for Micro-Fractures under Large Strains

Endochronic constitutive relations in viscoplastic theory for large strain domain are considered. It is assumed micro-fractures are initiated both in elastic and in non-elastic elements of deformed material. Two constitutive equations and two dilatation ones for elastic and non-elastic ranges are proposed. Dilatation parameters are introduced into strength condition for brittle and ductile fracture of materials.