Probabilistic Ultimate Strength Analysis of Cracked Marine-grade Aluminum Stiffened Plate Using Non-Intrusive Chaotic Radial Basis Function

Abstract

While ultimate strength analysis methods exist for steel marine structures, there remains a critical gap in understanding the probabilistic behavior of cracked aluminum stiffened plates, particularly in high-speed craft where operational uncertainties compound material and damage variabilities. This gap is addressed through the development of a novel probabilistic framework for analyzing the ultimate strength of cracked aluminum stiffened plates in high-speed craft by integrating nonlinear finite element analysis (NLFEA) with Non-Intrusive Chaotic Radial Basis Function (NICRBF). The framework systematically accounts for uncertainties in crack parameters (size, location, orientation) and material properties, while incorporating operational factors such as wave-induced loads and slamming effects. Through 10000 numerical simulations, it was demonstrated that crack length significantly influences ultimate strength variability (COV ranging from 0.268 to 0.353), while crack orientation affects mean ultimate stress between 253.92-295.73 MPa. For operational conditions, probability of failure increases markedly with vessel speed, reaching 0.994 at design velocity under 8m wave heights. The NICRBF approach provides an efficient computational framework while maintaining accuracy. These findings provide quantitative guidance for structural reliability assessment and safety-oriented design of high-speed aluminum vessels, particularly in determining operational limits based on wave height and speed combinations. The developed framework offers a practical tool for marine engineers to evaluate structural integrity under uncertain damage scenarios.