Rate dependent anisotropic plasticity model of titanium alloy for aerospace application
Résumé
Following an extensive experimental campaign carried out on a cold-rolled Ti-6Al-4V titanium alloy grade within a wide range of (low and high) strain rate, temperature and loading cases (tension, compression, shear), an advanced constitutive model is built within the irreversible thermodynamics framework following the internal variable procedure. Some key aspects such as texture-induced anisotropy (which manifests through orthotropy, kinematic hardening and tension/compression asymmetry), rate dependence, strain hardening and thermal softening are consistently accounted for. Material constants are calibrated using the software Zset and the model has been implemented in the commercial finite element computation code LS-DYNA. The latter has been employed to conduct numerical simulations at the structural scale for evaluating the predictive performances of the numerical version of the model