In this research, softening and ratcheting behaviors of stainless steel 304L cylindrical shells under displacement- control and force-control cyclic axial loading are studied. Experimental tests were performed by a servo-hydraulic INSTRON 8802 machine. The mechanical properties of specimens were determined according to ASTM E8 standard. Under force-control loading with non-zero mean force, ratcheting behavior is occurred on cylindrical shell and plastic strain accumulation continues up to collapse point of cylindrical shell. The rate of ratcheting strain became higher by using of the higher force amplitude. Under displacement control loading, softening behavior is observed and due to occurred buckling in compression zone, this behavior becomes more extreme. Also, cutout effect on cylindrical shells under these kinds of loadings has been studied and it has been observed that cutout causes softening and ratcheting behaviors in cylindrical shell extremely. Also effect of locations and sizes of cutouts on softening and ratcheting behavior are studies and results shows that increase of cutout radius shows more ratcheting strain than other specimens and rate of ratcheting strain is much higher than the others and reaches collapse point earlier than other specimens

Keywords