Michael Ortiz

TL;DR: This paper describes a local real-space variational formulation for orbital-free density functional theory, including the electrostatic terms and proves the convergence of the finite-element approximation including numerical quadratures for the variational formulations.

TL;DR: In this article, a universal relation for crack surface cohesion including surface relaxation is presented, where the energy and opening displacement are scaled appropriately with respect to N, the uniaxial elastic constant, the relaxed surface energy, and the equilibrium interlayer spacing, all energydisplacement curves collapse onto a single universal curve.

TL;DR: In this paper, an anisotropic cohesive model of fracture is applied to the numerical simulation of Coker and Rosakis experiments, and successfully predicts the dynamic fracture behavior, assuming that sufficient energy is supplied to the crack tip.

TL;DR: A theoretical framework for the analysis of localized failure in concrete is presented in this article, which is predicated upon the assumption that discrete failure planes arise as a result of a process of localization of damage.

TL;DR: The robustness and versatility of the approach, as well as the good quality of the resulting meshes, is demostrated with the aid of selected examples.