Ship structuresShip structure constructed from polyurethane-steel sandwichSandwich composites have shown promising mechanical properties, making them highly appealing for various marine applications. Nevertheless, ensuring their long-term durability and resistance to fatigue crack growth remains crucial for ensuring the safety and reliability of maritime operations. This study aims to address concerns related to fatigue crack growth and debondingDebonding. Through controlled loading conditions and rigorous data collection, the study employs regression analysis to establish mathematical relationships between fracture rates, material toughness, and other parameters. The primary objective is to predict fatigue crack growth and determine Paris lawParis law coefficients using this approach. The results reveal remarkably consistent Paris law coefficients across different initial crack lengths, averaging 1.68E−06 for C and 0.38 for m. These coefficients, integrated into the Paris lawParis law equation, provide fundamental insights into how cracks propagate in these materials. This research carries significant implications for the shipbuilding industry, offering valuable guidance for damage tolerance assessments and the effective utilization of advancedSandwichsandwich materialsSandwich material, ultimately contributing to the safety and reliability of maritime operations.