ON THE LOADING UNLOADING CONDITIONS OF INFINITESIMAL DISCRETE ELASTOPLASTICITY

This paper addresses the loading/unloading conditions of the discrete initial-value problem of plastic flow at infinitesimal deformations. A s in the continuum problem, it is established that the strain-space fo rmulation of the loading conditions is primary. Generalized trapezoida l and mid-point rules are discussed. The loading conditions establishe d for the general non-associated flow problem are shown to naturally r educe to well-known inequalities for flow rules obeying normality.