Cyclic behavior of SS316L cylindrical shells under pure torsional load: An experimental investigation

Ratcheting and softening characteristics of SS316L cylindrical shell under cyclic pure torsional load were studied, experimentally. Experimental tests were performed in torque-control and angle of torsion-control conditions by a Servo-Hydraulic INSTRON 8802 machine and the effect of torque amplitude, history loading, shape of cutout, and angle of torsion on the cyclic behavior of cylindrical shells were examined. Under torque-control loading with non-zero mean torque, ratcheting behavior occurred on cylindrical shells. The ratcheting angle and its rate increase with increasing mean torque. Under angle of torsion-control loading, softening behavior was observed and it was shown the reaction of shells can be divided into four stages, i.e. incubation, transition, steady-state and crack propagation. Finally, the numerical analysis was carried out by ABAQUS software using nonlinear isotropic/kinematic (combined) hardening model. The result demonstrated that the cyclic behavior of cylindrical shell under pure torsional load could be numerically simulated with a reasonable accuracy.