Multi scale method for modeling material failure

Project head: Prof. Dr.-Ing. Timon Rabczuk
Project employee: M.Sc. Pattabhi Ramaiah Budarapu
Funding period: 2010 - 2013


In this research project, a new adaptive multi scale method for modeling material failure will be investigated. It is based on Bridging Domain (BDM) coupling. Atomistic approach is adapted on the fine scale for accurate modeling of the material failure around the crack tip, while continuum approach is ensured in the far areas of crack tip. In other words on the coarse scale (macro scale) i.e the continuum level, the extended finite element methods (XFEM) is used, which allows to model the cracks without remeshing. The bridging between atomistic and continuum domains is implemented through BDM. The BDM is an overlapping domain decomposition method in which the atomistic and continuum energies are blended so that their contribution decay to their boundaries on the overlapping sub-domain. Compatibility between the continua and atomistic domains is enforced by a continuous Lagrange multiplier field. The advantages of BDM as compared to many other coupling techniques include:

1. FE nodes does not required to be placed at the position of the atoms.

2. It is capable of removing spurious wave reflections.

The computation becomes expensive with the size of the atomistic model in BDM. Hence techniques like adaptive refinement (moving atomistic models around the regions close to the crack tip) will be investigated. 3D dynamic crack models incorporating adaptive refinement is the final goal of the research.