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A spectral approach for discrete dislocation dynamics simulations of nanoindentation

Research paper by Nicolas Bertin, Vedran Glavas, Dibakar Datta Wei Cai

Indexed on: 08 Jun '18Published on: 13 May '18Published in: Modelling and Simulation in Materials Science and Engineering



Abstract

We present a spectral approach to perform nanoindentation simulations using three-dimensional nodal discrete dislocation dynamics. The method relies on a two step approach. First, the contact problem between an indenter of arbitrary shape and an isotropic elastic half-space is solved using a spectral iterative algorithm, and the contact pressure is fully determined on the half-space surface. The contact pressure is then used as a boundary condition of the spectral solver to determine the resulting stress field produced in the simulation volume. In both stages, the mechanical fields are decomposed into Fourier modes and are efficiently computed using fast Fourier transforms. To further improve the computational efficiency, the method is coupled with a subcycling integrator and a special approach is devised to approximate the displacement field associated with surface steps. As a benchmark, the method is used to compute the response of an elastic half-space using different types o...