A LARGE STRAIN EXPLICIT FORMULATION FOR COMPOSITES

E. B. LAS CASAS; S. OLLER; J. RUBERT; S. PROENÇA; E. OÑATE

Conferencia; 4th World Congress on Computational Mechanics; 1998

A geometrically nonlinear formulation for composites and the derived explicit dynamicfinite element program are presented. The relevant variables at each time step are mappedinto an equivalent isotropic space, where the integration of the rate constitutive equations isperformed. The evolution of the internal variables is calculated in the mapped spaces, and the results mapped back to the real stress space. The formulation allows the treatment of general anisotropic materials and multiphase composite materials using the mixing theory. A consistent formulation for small elastic and large plastic strains, and the updating of themapping tensors for each new spatial configuration permits the analysis of a wide range ofcomposite structures. Each material is considered with its behavior dictated by its ownmechanical proprieties. The model allows a fully nonlinear analysis combining differentmaterial models, such as damage in one compounding substance, elasto-plastic behavior inother, while a third substance behaving elastically.