Forecasting the Ultimate Strength of Designed Thin-Walled VLCC Structures Based on Imperfection and Pressure Severities: Benchmarking and Developing an Empirical Formula
Abstract
The increasing number of accidents involving Very Large Crude Carriers (VLCCs) has heightened concerns regarding ship safety and structural integrity. Stiffened panels have emerged as a crucial element in effectively reinforcing ship structures without significantly adding weight. Reliability analysis has been extensively conducted to evaluate the strength of stiffened panels with various parameters. However, the effects of lateral pressure parameters on structural strength have not received adequate attention in reliability analyses, and they have only been presented as single values. This necessitates a more extensive investigation to determine the distributional effects of lateral pressure on initial deflection enhancement and ultimate strength value reduction. To address this gap, the current study introduced modifications to parameters such as the slenderness ratio, span/bay ratio, yield strength, initial imperfections, and pressure. A total of 216 data points were obtained through numerical finite element method (FEM) simulations using ABAQUS. The obtained ultimate strength values were statistically analyzed using a T test to explore the correlations among the parameters. Subsequently, a regression analysis was conducted to construct an empirical formula. The resulting empirical formula demonstrated remarkable accuracy, with a mean absolute percentage error (MAPE) of merely 0.801% when compared to the FEM numerical results, thus substantiating its validity as an effective and efficient solution for predicting ultimate strength values influenced by pressure.