Probabilistic ultimate strength (US) distribution against environmental casualties: Stiffened panel under imperfection

Abstract

In this study, the ultimate strength of a stiffened panel, which is one of the important components of ship structure, was analyzed by considering the effects of initial imperfection and geometric aspects with variations of random amplitude. The initial imperfection is influenced by local, torsional, and column imperfection modes, while the span/bay and plate slenderness ratios influence the geometric aspects. The analysis was carried out using the ANSYS software’s finite element method (FEM). To calculate the value of normalized strength, the regression calculation stage is carried out, the input is random amplitude with a limit of 0% to 100%, and the normal distribution calculation is shown in the probabilistic distribution. The results of this study indicate that the initial imperfection decreased the ultimate strength of the stiffened panel. The short heavy model has the highest average normalized strength value compared to the other models of variations, which is equal to 0.928. In contrast, the long light model has the lowest average normalized strength value, equal to 0.618.