engleski

An Efficient Modelling of Anisotropic Large Strain Elastoplastic Deformation Responses

Formulation of large strain elastoplastic model for anisotropic materials based on multiplicative decomposition of deformation gradient is considered. In order to achieve formulation invariant to finite rotations, is assumed to be material-like tensor. An anisotropic elastic constitutive law is described by means of free energy that is function of elastic right Cauchy-Green tensor and structural invariants defining material orientation. This dependency is formulated by using so called integrity basis. An anisotropic yield function, described by non-symmetric Eshelby-like stress tensor and further structural tensors, is developed. In order to obtain yield function as an isotropic function of material invariants, integrity basis are made by using theorems for functions with non-symmetric arguments. The model considers non-linear isotropic hardening, as well. An accurate integration algorithm employing exponential map is developed. In order to ensure a high convergence rate in the global iteration approach, an algorithmic tangent operator for anisotropic multiplicative inelasticity is for the first time derived. Various numerical examples show robustness and efficiency of the proposed algorithm. The influence of anisotropy on finite elastoplastic deformation responses is also considered.

multiplicative inelasticity; anisotropic elastic law; anisotropic yield function; exponential map

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