Computational aspects of disturbed state constitutive models

Abstract

Disturbed state concept (DSC) provides a unified basis for constitutive modelling including elastic, plastic and creep deformations, microcracking, damage and softening, stiffening, and cyclic fatigue under thermomechanical loading. It includes intrinsically regularization, localization, characteristic dimension and avoidance of spurious mesh dependence. It also leads to a new procedure for mesh adaptivity, particularly in zones experiencing significant microcracking and softening. The idea of the critical disturbance allows identification of the initiation of fracture and its growth as a consequence of microcrack coalescence. The DSC is implemented in nonlinear finite element procedures and a number of problems have been solved, and results are evaluated and compared with solutions by other methods so as to illustrate the foregoing capabilities of the model.