On micro-to-macro connections in strong coupling multiscale modeling of softening materials

In this contribution we describe a methodology for the multiscale analysis of heterogeneous quasi-brittle materials. The algorithm is based on the finite element tearing and interconnecting FETI [1] method cast in a non-linear setting. Adaptive multiscale analysis is accounted for with the use of selective refinement at domains that undergo nonlinear processes. We focus on the micro-to-macro connection method which constitutes the strategy to handle incompatible interfaces arising from the connection of non-matching meshes. The behaviour of standard collocation and average compatibility techniques is assessed for a multiscale analysis of damage propagation in a quasi- brittle material. The choice of the connection strategy has an influence on the overall response and the computational cost of the analysis.