Compression test for plastic anisotropy characterization using optical full-field dis-placement measurement technique

In this work, a constitutive law, its identification and its validation for TA6V titanium alloy are presented. The material characteri-zation is achieved by quasi-static monotonic tensile and compression tests at several strain rates and in three orthogonal material orientations. Constitutive model as Johnson-Cook which describes the strain rate sensitivity of the plastic material response is used in order to identify the initial yield locus at a common strain rate (10-3 s-1). The macroscopic orthotropic yield criterion chosen is the well-known CPB06 proposed by Cazacu et al., which describes both the tension/compression asymmetry and the anisotropic behavior of hcp metals and alloys. Voce type isotropic hardening model is used for simplicity reasons. A compression test on ellipsoidal cross-section specimen is selected for validation purpose, where 3 Digital Image Correlation 3D systems are used in order to acquire the evolution of the full field displacement/strain during the test. Coulomb friction coefficient between the dies and the specimen is computed by means of inverse modelling. A good agreement on the prediction of the load as a function of axial displacement of the specimen is found.