Michael Ortiz

TL;DR: In this paper, the authors review and further develop the subject of variational integration algorithms as it applies to mechanical systems of engineering interest, and present selected numerical examples which demonstrate the excellent accuracy, conservation and convergence characteristics of AVIs.

TL;DR: In this article, the subdivision shell elements of Cirak et al. were extended to the finite-deformation range, allowing for finite membrane and thickness stretching, as well as for large deflections and bending strains.

TL;DR: In this paper, a method for automatically extending small-strain state-update algorithms and their corresponding consistent tangents into the finite deformation range within the framework of multiplicative plasticity is presented.

TL;DR: In this paper, a phase-field theory of dislocation dynamics, strain hardening and hysteresis in ductile single crystals is developed, which is analytically tractable, in the sense that the complexity of the calculations may be reduced, with the aid of closed form analytical solutions, to the determination of the value of the phase field at point-obstacle sites.

TL;DR: In this paper, a large-scale atomic resolution simulation of nanoindentation into a thin aluminum film using the recently introduced quasicontinuum method is presented to study the initial stages of plastic deformation under the action of an indenter and obtain both macroscopic load versus indentation depth curves, as well as microscopic quantities such as the Peierls stress and density of geometrically necessary dislocations beneath the indenter.