Abstract:
In this study, the plastic deformation behaviour of five different types of materials have been investigated by performing combined telsion and torsion experiments on thin-walled tubular specimens. The effects of annealing, cold working and age hardening on the yield curves of aluminum have been determined. Casted aluminum and polyethylene specimens were also tested under the same stress conditions. The validity of theoretical yield criteria and the normality condition of the plastic strain vector to the yield curves have also been investigated. It was observed that Mises criterion yielded better representation for the yield curves of the isotropic materials.
