CONCEPT OF THE LIMIT YIELD CONDITION IN SHAKEDOWN THEORY

The concept of the limit yield condition is introduced which makes pos sible the extension of both the static (Melan) shakedown conditions, a nd the necessary kinematic (Koiter) one to a class of classical consti tutive material models with internal variables. This class includes ma terial models with both bounded and unbounded nonlinear isotropic stra in-hardening. It is assumed that the yield conditions are convex with respect to stresses for all admissible values of the internal variable s, but convexity in the internal variables is not assumed. Connections are established between the response of elastic perfectly plastic bod ies to cyclic loading and that of bodies with internal variables. A me thod for estimating the limit yield condition is developed, and an exa mple of this application is given. (C) 1997 Elsevier Science Ltd.