Two-scale model for failure analysis of heterogeneous materials: numerical validation

S TORO; PJ SÁNCHEZ; PJ. BLANCO; A E. HUESPE; R. A. FEIJÓO

Praga

Congreso; CFRAC 2013: The Third International Conference on Computational Modeling of Fracture and Failure of Materials and Structures; 2013

ECCOMAS

In recent works ([1] and [2]), the authors have presented a new variational multi-scale formulation devised to modeling the failure of heterogeneous materials (Failure-Oriented Multi-scale Formulation (FOMF)).Two well-separated length scales are considered in the FOMF. The macro model describes the failure processes that are taking place at the micro model by means of a cohesive interface which is mechanically characterized through a traction T vs. separation relation. The failure processes at the microscopic level are modeled using a RepresentativeVolume Element (RVE). The traction T is defined as a function of  by means of a computational homogenization technique that considers two transfer operators: i) a nonhomogeneous strain injection operator that transfers the crack opening , from the macro to the microscale; ii) as consequence of a well established variational principle and the adopted approach, it is derived a stress homogenization operator which determines T as a results of a homogenization of the stress field at the RVE level. One of the main characteristics of this technique is its full variational consistency, as well as, that the vector T is objective with respect to the micro-cell size taken to perform the material failure analysis at the microscopic level.