Stress-strain responses for continuous orthogonal strain path changes with increasing sharpness

In this article a series of non-proportional orthogonal tests with continuous strain paths are presented. Mild steel was investigated on a biaxial test device that was specifically developed to examine strain path sensitivity. It is shown that a gradual strain path change shows a gradual increase in stress. However, experiments with increasing sharpness in the strain path change show an overshoot in stress which is a typical feature of stress–strain curves from discontinuous strain path changes.