Vol.25, No.1, 2025, pp. 79–88
https://doi.org/10.69644/ivk-2025-01-0079

The field of ship structure analysis has witnessed considerable progress marked by the proliferation of analytical formulas proposed by researchers as efficient tools for predicting the strength of ship structures, particularly those involving plate configurations. However, a comprehensive review of the existing literature underscores a notable gap - existing studies predominantly focus on a singular aspect, namely plate slenderness when predicting ultimate strength. In a bid to address this limitation and account for the myriad uncertainties inherent in plate structure calculations, this study adopts a nuanced approach. Numerical methods are employed, systematically varying geometric parameters such as b/t ratio and yield strength, alongside introducing initial imperfections in the form of local plate imperfection modes. Further enhancing the analysis complexity, amplitude severity is modified across amplitude, ranging from 25 % to 300 %, encompassing scenarios of slight, average, and severe severity. Leveraging the capabilities of ANSYS^® APDL and MATLAB^®, an extensive dataset comprising 126 data points is collected and processed. These efforts result in the derivation of a formula tailored for calculating plate normalised strength. Implemented as a quadratic equation, the derived formula demonstrates a remarkable capacity to accurately predict data points characterised by significant deviations. Notably, its performance is gauged against numerical results, revealing a minimal standard error of approximately 0.023. The close alignment observed when comparing the derived formula with recent previous formulas further substantiates its potential as a viable solution for estimating normalised strength, particularly in scenarios influenced by geometric modifications and initial imperfections.

Keywords: • plate • VLCC • ultimate strength • initial imperfection • derived formula