Water impact damage considering hydro-plastic interactions: Extensive experimental and numerical validation, and structural design recommendations

Abstract

Water impact damage can occur for ocean structures subjected to extreme waves as well as aeronautical vehicles during emergency water landing. The problem involves complicated fluid structure interaction (FSI) effects between large plastic structural deformations and fluid flow pressures, known as hydro-plasticity, and is not well understood. In 2019, we (Yu et al. [1]) derived a novel hydroplastic solution for water impact damage of beams and stiffened panels considering the mutual coupling effect. This paper utilizes results from model tests, real world wave impact accidents and coupled FSI numerical simulations to verify comprehensively the accuracy of the hydroplastic model in terms of the predicted structural damage and pressure histories. As most design standards use suggested pressure curves for designing against extreme wave impacts in the maritime and offshore industries, the pressure histories predicted by the hydroplastic model are reapplied to the structures to calculate the structural responses using nonlinear finite element analysis (NLFEA). This is to test if the generated pressure histories can reproduce the water impact damage and be used as suggested design pressure curves. Finally, a new design method is suggested based on the hydroplastic slamming model for the design of ocean structures against extreme wave impacts. The proposed design approach suggests using impact velocities rather than design pressures in current design standards, as the main design parameter, the value of which should meet required annual exceedance probability levels. The proposed design approach represents clear improvement and is useful for reliable and cost-effective design of structures against extreme water impacts.