Large Strain Explicit Formulation for Anisotropic Materials based on Isotropic Mapped Elastoplastic Models

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

Congreso; XVIII Congreso Ibero Latino Americano de Métodos Computacionales en Ingeniería.; 1997

A large strain formulation for the analysis of anisotropic bodies and its implementation in anexplicit dynamic finite element code are presented. The relevant variables at each spatialconfiguration are mapped to an equivalent isotropic body. The integration of the rateconstitutive equations is made in a fictitious stress using standard algorithms developed forisotropic materials. The evolution of the internal variables is also calculated in the mappedspace. The results are then mapped back to the real stress space. The dynamic integrationscheme uses lumped element mass matrices, resulting in a conditionally stable explicitintegration algorithm. The proposed formulation allows the treatment of general anisotropicmaterials and, as an extension, composite multiphase materials using the mixing theory.Example problems are presented and discussed.