NUMERICAL PROCEDURES OF UPPER-BOUND APPROXIMATION OF SHAKEDOWN LOADS AND ITS APPLICATION IN ENGINEERING

There exist two types of failure modes including alternating plasticity and incremental collapse for elastoplastic structures subjected to varied loading. The purpose of shakedown analysis is to determine maximum range of load variation. The kinematical-type shakedown analysis is to assess an upper bound of shakedown load based on kinematically-admissible incremental plastic strain fields which are difficult to be constructed for actual structures. Hence, some constraint conditions in the kinematic shakedown theorem were released by König and two shakedown criteria respectively for alternating plasticity and incremental collapse were obtained. This simplification makes numerical solution for upper bound of shakedown loads possible. In this paper, based on kinemtatically-type shakedown criteria for incremental collapse and for alternating plasticity, computational procedures for avoiding incremental collapse and alternating plasticity are formulated and used to evaluate bearing capacity of structures and soil foundations under transient or cyclic loading pattern.