J. Cirne, R. Dormeval, et al.
J. Phys. IV France 134 (2006) 325-330
Theoretical and numerical study of strain localization under high strain rate solicitationN. Ranc1, R. Raynal1, L. Taravella2, V. Pina1 and P. Hervé1
1 LEEE, E.A. 387 – Université Paris X, 1 chemin Desvallières, 92410 Ville d'Avray, France
2 CEP DGA/DET, 16 bis, Avenue Prieur de la Côte d'Or, 94114 Arcueil cedex, France
Published online: 26 July 2006
Our study deals with the dynamic behavior of metallic materials and in particular of titanium alloy TA6V. For high strain rates, we can notice the occurrence of a phenomenon called adiabatic shearing. This phenomenon is about a plastic instability, which results in the appearance of a strain localization in narrow bands. In this paper we developed a thermo mechanical model to reproduce the formation and the propagation of adiabatic shear bands. A Johnson Cook thermo visco plastic behavior law was chosen for the titanium alloy TA6V. The law parameters were identified from static and dynamic torsion tests at various temperatures between ambient and C. A 2D numerical simulation of torsion test was performed with the explicit finite elements code Abaqus. The thermo mechanical coupling and the heat conduction are taken into account. A roughness defect was inserted in the centre of a torsion specimen. The results showed that the strain of localization and the shear band speed increase when the amplitude and the size of the defect decrease.
© EDP Sciences 2006