Continuous strain path change simulations for sheet metal

The plastic behavior of a material undergoing continuous strain path changes, from plane strain to simple shear, was simulated for a mild steel. A distortional hardening model was employed to capture the Bauschinger effect and latent hardening. The simulations were conducted by direct application of the constitutive equations with simple boundary conditions and by using a finite element code in which the distortional hardening model was previously implemented. Depending on the rate of path change, the simulations resulted in different combinations of plastic responses including the Bauschinger effect, transient hardening, flow stress overshooting and strain hardening stagnation. The simulated stress-strain curves were found to be in good agreement with experimental results published by van Riel and van den Boogaard (2007).