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2011
Journal Article
Titel
The atomic finite element method as a bridge between molecular dynamics and cintinuum mechanics
Abstract
On cutting tools for high performance cutting (HPC) processes or for hard-to-cut materials an increasing importance show the so-called super-lattice coatings with hundreds of layers each of them having only few nanometres of thickness. Homogeneity or average material properties based on the properties of single layers are not valid in these dimensions any more. Consequently, continuum-mechanical material models cannot be used for modelling the behaviour of nano-layers. Therefore, the interaction potentials between the single atoms should be considered. A new, so-called Atomic FEM (AFEM) is presented. In the AFEM the inter-atomic bonds are modelled as non-linear spring elements. The AFEM is the connection between the molecular dynamics (MD) method and the Crystal Plasticity FEM (CPFEM). The MD simulates the atomic deposition process. The CPFEM considers the behaviour of anisotropic crystals using the continuum-mechanical FEM. On one side, the atomic structure data simulated by MDdefines the interface to AFEM. On the other side, the boundary conditions (displacements and tractions) of the AFEM model are interpolated from the CPFEM simulations. In the AFEM the lattice deformation, the crack and dislocation behaviour can be simulated and calculated in the nanometer scale.