Use of plane-strain tension and shear tests to evaluate yield surfaces for AA1050 aluminium sheet

摘要

Plane-strain tension and shear tests were carried out for a fully annealed AA1050 sheet. The tests were simulated numerically with a commercial finite element method (FEM) code using an anisotropic plasticity model including the Yld2004-18p yield function, the associated flow rule and isotropic hardening. The advanced yield function was calibrated by three different methods: using uniaxial tension data combined with FC-Taylor model predictions of the equibiaxial yield stress and r-value, using 201 virtual yield points in stress space, and using a combination of experimental data and virtual yield points (i.e., a hybrid method). The virtual stress points at yielding were provided by the recently proposed Alamel model with the so-called Type III relaxation (Alamel Type HI model). FEM simulations of the tests were then made with parameters of Yld2004-18p identified by these three methods. Predicted force-displacement curves were compared to the experimental data, and the accuracy of the parameter identification methods for Yld2004-18p was evaluated based on these comparisons.