Computational multiscale modelling of localized ductile failure

In forming processes, polycrystalline metals undergo finite plastic deformation. Within these heterogeneous materials, the applied large deformations may trigger microstructural damage mechanisms due to evolving microcracks and -cavities. At the macro scale, such mechanisms express in localized plastic deformations eventually causing ductile failure.

Many phenomenological material models capture ductile damage. However, to flexibly incorporate the underlying the governing microstructural properties and damage  mechanisms, a multiscale framework is needed. The few recent numerical multiscale works on localized failure are limited to brittle microdamage. Therefore, the goal of this project is to provide a computational multiscale framework for the modelling of localized failure stemming from a microstructure undergoing ductile damage.

The project starts with multifield material modelling of ductile gradient inelasticity for the hetergeneous meso level. A computational homogenization is customized for such material model involving additional degrees of freedom using a consistent multiscale linearization. Ultimately, the localized failure is captured by a computational interface homogenization for the underlying heterogeneous mesostructure undergoing ductile damage. The expected
result is a versatile framework for the multiscale modelling of ductile failure in  heterogeneous media, which reflects occuring size effects and provides the basis for the simulation of a broad range of further complex and physically-based models for the inelastic mesostructure.