Experimental study of SS316L cantilevered cylindrical shells under cyclic bending load

In this research, softening and ratcheting behaviors of SS316L cantilevered cylindrical shells under cyclic bending load were investigated. Experimental tests were carried out by a Servo-Hydraulic INSTRON 8802 machine. Force-control and displacement-control loadings were applied and the effects of displacement amplitude, mean force, loading history and cutout position were examined. Under displacement-control loading, softening behavior was observed due to growth of ovalization and it was shown that as the displacement amplitude increases, softening rate and density of plastic energy increase. Accumulation of the plastic strain or ratcheting phenomenon occurred under force-control loading with nonzero mean force. Increase of the mean force accompanied with an increase in the accumulation of the plastic deformation and its rate. In loading history, it was seen that prior load with higher force amplitude retards the ratcheting behavior and plastic deformation of subsequent load with smaller force amplitude. In addition, due to sensitivity of cutout to the bending moment, as the position of the cutout changes from the middle of shell towards the cantilevered end, the accumulation of the plastic deformation increases.