A BIAXIAL CYCLIC PLASTIC ANALYSIS FOR CYLINDRICAL SPECIMENS

Abstract The cylindrical specimen is a common configuration adopted for biaxial fatigue testing. A rigorous yet practical analysis is presented here under the framework of incremental plasticity. The cyclic stress‐strain curve is obtained from four different plasticity models, and correlated with twenty‐six in‐phase biaxial tests on En15R steel. Stabilized hysteresis loops can also be derived based on the cyclic stress‐strain curve under a J2‐kinematic hardening formulation with special consideration of the rounding transition at the instant of yielding. A correlation for the hysteretic strain hardening exponent N is required for materials that exhibit non‐Masing behaviour; i.e. do not allow a full description of hysteresis loops from knowledge of the cyclic stress‐strain curve. The solution is further generalized to out‐of‐phase loading, where the rotation of the active stress state around the yield surface is illustrated. This compares favourably with ten out‐of‐phase tests on En15R steel.