Hydroelastic Assessment of Different High-Speed-Vessel Stiffened Panel Designs

In this paper, the hydroelastic response of the bottom panel on high-speed craft during slamming events is investigated with a numerical fluid-structure-interaction (FSI) method. The FSI method tightly couples computational-fluid dynamics for the fluid solution and finite-element analysis for the structural response. The volume-of-fluid approach is use to capture the air-water interface and the time dependent wetness of the body elevating the water. The structure discretization is performed by a linear-dynamic finite-element method with modal decomposition. The tightly-coupled interaction between the structure and fluid domains allows for an accurate prediction of structural response during slamming. The methodology is used to investigate the design of two bottom hull stiffened panel arrangements equivalent from the perspective that each meets the requirement of minimum section modulus, shear area, and plate thickness. Numerical fluid and structural mesh selection are performed separately based on the quantities of displacement, structure modal energy, and force. Rigid panel slamming simulations are used for mesh quality assessment, and two-way coupled simulations provide the global hydroelastic panel response. It is found that the design with a thinner plate and a larger number of small stiffeners exhibits smaller displacement, strain, and stress during the same impact event compared to the design with a thicker plate and a fewer number of larger stiffeners. Hydroelastic effects are found to be significant for lower panel deadrise angle which increases displacement, strain, and stress for both designs.