A strain-space plasticity theory and numerical implementation

This thesis sets forth an alternate version of plasticity which closely parallels the traditional theory but interchanges the roles of stress and strain. As a result, the new formulation gives stress as a functional of strain, rather than the reverse, and is thus attuned to the needs of the dynamicist. In the case of a single loading surface, the two versions of plasticity are shown to be equivalent when the model parameters are appropriately selected. A similar though less satisfying result is obtained for formulations involving a plurality of loading surfaces. The strain-space formulation is coded for numerical solution, with provision for a variable number of loading surfaces. The numerical algorithm is tested for accuracy in the handling of perfect plasticity, and the results are compared with those given by three commonly-used stress-space algorithms. The new algorithm is then interfaced with a finite element code and used to study the response of a foundation resting on an elastoplastic half-space.