Fatigue life prediction of shear failure dominated foam cored sandwich composite hull panels under variable water-slamming conditions

Abstract

This paper presents a hybrid computational-empirical fatigue failure prediction model for shear failure dominated foam cored sandwich hull structures subjected to variable water slamming conditions. The proposed approach combines finite element analysis with core material experimental characterization published in the literature. Core shear stress and stress rate histograms are constructed by interpolation of simulated finite element results using experimentally determined hydrodynamic pressure distribution. An exponential fatigue damage accumulation model based on core shear modulus degradation is presented and implemented to predict slamming fatigue life of sandwich panels. As a result of the present study, it was determined that sandwich panels experienced the highest core shear stresses and stress rates in the proximity of the right-hand support. Results demonstrated that under variable slamming conditions, fatigue performance of cored sandwich panels is stress-sequence dependent. Sandwich panel fatigue life showed a significant reduction with increasing impact velocity and decreasing deadrise angle.