Third M.I.T. Conference on Computational Fluid and Solid Mechanics June 14–17, 2005  

Computational method for mapping continuum deformations to crystal lattices containing defects

Peter W. Chung*, John D. Clayton
US Army Research Laboratory, AMSRL-CI-HC, Aberdeen Proving Ground, MD 21005, USA

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ABSTRACT
Computational multiscale methods that perform concurrent simulations of atoms and solid continua generally rely on classical assumptions for kinematics, such as the Cauchy-Born approximation, for deformations of perfect crystals. For the treatment of crystal defects, such assumptions do not apply and one is left only with performing full-scale atomistic energy minimizations. We present interim progress on an approach based on homogenization to enable continuum notions of deformations to apply to defected lattices. Using a decompositional kinematical representation, we present a single parameter line search method for the minimization procedure, with the intent of substantially reducing the computational cost.

Keywords:  Multiscale; Finite elements; Atomistics; Plasticity; Large deformation

* Corresponding author. Tel.: +1 410 278 6027; Fax: +1 410 278 4983; E-mail: pchung@arl.army.mil