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 torquecontrol 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.

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