ELASTIC-PLASTIC STRESS-STRAIN CALCULATION IN NOTCHED BODIES SUBJECTEDTO NONPROPORTIONAL LOADING

An analytical method for calculating notch tip stresses and strains in elastic-plastic isotropic bodies subjected to non-proportional loadin g sequences is presented. The key elements of the two proposed models are generalized relationships between elastic and elastic-plastic stra in energy densities, and the material constitutive relations. These tw o models form the lower and the upper limits of the actual energy dens ities at the notch tip. Each method consists of a set of seven linear algebraic relations that can easily be solved for elastic-plastic stra in and stress increments, knowing the hypothetical notch tip elastic s tress history and the material stress-strain curve. Results of the val idation show that the proposed methods compare well with finite elemen t data and each solution set forms the limits of a band within which a ctual notch tip strains fall.