Abstract
Pressure vessel is required to suppress the progressive deformation, namely ratcheting, which may be caused by secondary cyclic loading under the certain combination of primary stress. Pressure vessel generally contains the component such as tube-sheet structure where stress concentration is caused under pressure or thermal loading due to the reason of the geometrical configuration. The simplified method for ratcheting can not accurately predict the accumulated strain in such a portion having stress concentration, since the stress changes greatly in the localized region. Experiment is carried out for a rectangular plate with a circular hole using SUS 304 material under zero-to-tension cyclic loading to clarify the fundamental feature of ratcheting. The finite element analysis is applied to clarify the mechanism of the ratcheting or progressive strain in the structure with stress concentration.
