INVESTIGADORES
SANCHEZ Pablo Javier
congresos y reuniones científicas
Título:
A variational multiscale model for fracture
Autor/es:
P.J. SÁNCHEZ; S. TORO; P.J. BLANCO; A.E. HUESPE; R.A. FEIJÓO
Lugar:
Vienna
Reunión:
Congreso; European Congress on Computational Methods in Applied Sciences and Engineering, ECCOMAS 2012; 2012
Institución organizadora:
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Resumen:
A two-scale variational formulation for modeling fracture problem of heterogeneous materials with softening, induced by strain localization and failure phenomena at micro scales, is here summarized. Also, some issues related with the numerical implementation of the model are addressed. The model follows the recent proposal of Sanchez et al. [1]. It considers two coupled mechanical problems at different physical length scales, denoted as macro and micro scales, respectively. Every point, at the macro scale, is linked to a Representative Volume Element (RVE), and its constitutive response emerges from a consistent homogenization of the micro-mechanical problem. At the macroscopic level, the initially continuum body is allowed to develop a strong discontinuity kinematics, a cohesive crack, after the macroscopic point fulfills a given failure criterion. The micro RVE model is used to drawn the homogenized stress in the complete loading process: i.e. during the evolution of the continuum as well as during the strong discontinuity kinematics regimes. Both, macro and micro, scales are discretized with the Finite Element Method. Then, a unified and systematic algorithmic treatment, for imposing the required kinematical boundary conditions on the RVE model, is provided. As specific cases of boundary conditions that can be handled with this numerical implementation are the: i) linear, ii) periodic or iii) minimal kinematical constraints for the standard homogenization procedure, as well as, the new kinematical constraints required by the multiscale cohesive model formulation. Numerical examples shown the objectivity of the formulation, the capabilities of the new multi-scale approach to model material failure problems, as well as, the flexibility to impose different kind of kinematical boundary conditions on the RVE.
