Pages 55-66
This is a report on stress analysis of a semi-membrane tank for an LPG carrier by an FEM program for contact problems. To precisely evaluate the necessary fracture strength of a cargo tank defined as Type B Tank in the IMCO Gas Carrier Code (the current IGC Code), it is indispensable to accurately analyse the stresses which will be caused in the cargo tank by various loads. However, unlike the independent tank, the usual linear elastic stress analysis method is not applicable in the semi-membrane tank, because its behavior depends on the clearance between the tank and its surrounding structures and on the frictional interaction force between them. Therefore, for the purpose of stress analysis of a semi-membrane tank for an LPG carrier, we developed an FEM program for contact provlems involving a thin -plate structure, and from a comparison between the results of the analysis by this program and those by various theories and experiments, we confirmed that the program developed has sufficient accuracy to evaluate the behavior of and stresses in an actual semi-membrane tank.
