Date of Award
Doctor of Philosophy (PhD)
Civil and Environmental Engineering
George Z. Voyiadjis
A constitutive model is formulated for anisotropic continuum damage mechanics using first elasticity and then finite strain plasticity. The formulation is given in spatial coordinates (Eulerian reference frame) and incorporates both isotropic and kinematic hardening. The von Mises yield criterion is modified to include the effects of damage through the use of the hypothesis of elastic energy equivalence. A modified elasto-plastic stiffness tensor that includes the effects of damage is derived within the framework of the proposed model. The damage variable used represents average material degradation which reflects the various types of damage at the microscale level like nucleation and growth of voids, cavities, micro-cracks and other microscopic defects. Numerical implementation of the proposed model includes the finite element formulation where an Updated Lagrangian description is used. The basic example of finite simple shear is solved. The problem of crack initiation is investigated for thin elastic and elasto-plastic plates with center cracks that are subjected to inplane tension.
Kattan, Peter Issa, "An Anisotropic Finite Plasticity Model for Continuum Damage Mechanics." (1989). LSU Historical Dissertations and Theses. 4852.