Constitutive modeling of a commercially pure titanium: validation using bulge tests

Benoit Revil-Baudard (1) , Elisabeth Massoni (2)

1 MAE - UC San Diego - Department of Mechanical and Aerospace Engineering [Univ California San Diego]
2 CEMEF - Centre de Mise en Forme des Matériaux

In this paper, mechanical tests aimed at characterizing the plastic anisotropy of a commercially pure α-titanium sheet are presented. Hemispheric and elliptic bulge tests conducted to investigate the forming properties of the material are also reported. To model the particularities of the plastic response of the material the classical Hill [1] yield criterion, and Cazacu et al. [2] yield criterion are used. Identification of the material parameters involved in both criteria is based only on uniaxial test data, while their predictive capabilities are assessed through comparison with the bulge tests data. Both models reproduce qualitatively the experimental plastic strain distribution and the final thickness of the sheet. However, only Cazacu et al. [2] yield criterion, which accounts for both the anisotropy and tension-compression asymmetry of the material captures correctly plastic strain localization, in particular its directionality. Furthermore, it is shown that accounting for the strong tension-compression asymmetry in the model formulation improves numerical predictions regarding the mechanical behavior close to fracture of a commercially pure titanium alloy under sheet metal forming processes.

Mots clés: Anisotropy; Fracture; Numerical models; Plastic deformation; Sheet metal; Titanium; Titanium alloys; Titanium sheet Commercially Pure titaniums; Mechanical behavior; Numerical predictions; Plastic anisotropy; Plastic strain localization; Predictive capabilities; Strain distributions; Tension-compression asymmetry

Domaines: Mécanique des matériaux [physics.class-ph]

Benoit Revil-Baudard, Elisabeth Massoni. Constitutive modeling of a commercially pure titanium: validation using bulge tests. Journal of Physics: Conference Series, 2016, 734, Part B, pp.32057. ⟨10.1088/1742-6596/734/3/032057⟩. ⟨hal-01411663⟩