Place: Seminar of Graduate School 'Multiscale Methods for Interface Coupling' (MUSIC) at Leibniz-Universität Hannover, Germany
This talk presents the theoretical foundations of a novel, streamlined Quasicontinuum (QC) method for the nano-to-micro scale transition via atomic coarse-graining at 0 K. The method is as a finite element method and can be seen as a direct off-spring of lattice statics. Its key ingredients will be explained in comparison and contrast to the prominent first QC-version, which is based on Cauchy-Born elasticity along with a domain-decomposition into local and nonlocal domains. A special focus of this talk is on the physical consistency at interfaces for the intended seamless scale-transition and on the conservation of the variational structure of the method. From the numerical side, we discuss crucial aspects for the accuracy and efficiency of the method. It also addresses adaptive mesh-refinement and proposes novel algorithms for numerical quadrature and energy minimisation. The performance of the computational framework is assessed in representative examples ranging from gentle (elastic) surface relaxations up to localised plastic deformations.