Direct and Inverse Characterization of the Asymmetric Hardening Behavior of Bulk Ti64 Alloy

Abstract

This work focuses on the evaluation of the calibration strategy of the CPB06 asymmetry parameter k and its influence on the predictive behavior of the model at large deformations for Ti64. The direct identification strategy is based on fitting the model with experimental strain hardening data up to the onset of plastic instability. The inverse strategy is performed by reducing the prediction errors of the load–displacement curves of both the cylindrical bar tensile test and the elliptical cylinder compression test. Both strategies use an orthotropic tensor of the CPB06 criterion previously identified from experiments performed in all three dimensions. The results presented quantify the maximum error achieved by each method in terms of elongation and load predictions for specimens with different stress states.

Keywords

• plastic instability
• identification strategy
• tension–compression asymmetry
• CPB06