Computational multiscale modeling of localized ductile failure

In this work, a multiscale method to predict size-effects in the inelastic regime of materials with an inherent characteristic length is presented. The classical micromorphic formulation, which incorporates such a characteristic length as a material parameter, is adapted to describe inelastic phenomena such as elasto-plasticity and ductile damage for finite deformations. A multiscale framework, in which the derived micromorphic-type models are embedded for the description of the mesostructure, is derived to circumvent computationally costly single-scale computations of mescoscopically heterogeneous materials. Since heterogeneous mesostructures cannot only be found in bulk materials but also in thin material layers, the computational homogenization scheme is modified by the use of macroscopic element exploiting interface kinematics. A focus is set on the consistent linearization, which ensures computational efficiency, in a symbolic-numeric approach suited for the implementation with an automatic-differentiation-based software.