Coupling of plastic effects with a rate-dependent surface energy based micromechanical damage model.

摘要

This thesis presents a rate-dependent damage model coupled with a rate-independent plasticity model simulating quasi-brittle materials under highly dynamic loading. This is a modification of the surface energy based fracture approach in the Dominant Crack Algorithm (DCA) to account for plasticity using the von Mises yield criterion and a non-linear hardening function. The methodology for tightly coupling the damage and plasticity algorithms is presented and numerical results from a loosely coupled approach are provided for Silicon Carbide for numerous uniaxial cyclic load cases. The results demonstrate the anticipated plastic response characteristics. A limited comparison of experimental concrete behavior with numerical simulations is also performed, showing that the new algorithm is able to capture the main loading responses.An investigation into sensitivity of the unmodified DCA to initial crack size and density is also performed, showing very different behavior across the range of values tested.