Finite element simulation of composite ship structures with fluid structure interaction

A finite element tool for structural analysis of a composite multi-hull structure is developed. Two-way fluid structure interaction (FSI) is implemented by coupling finite element analysis (FEA) and computational fluid dynamics (CFD). FEA models have been developed using sandwich construction having composite face sheets and foam core. Fluid domain is modeled using a CFD code, CFX and a wave motion is simulated based on Sea State 5. FSI module is then used to connect FEA with the CFD code. Dynamic response of the hull is generated in time domain. A critical area with high stress gradient is chosen and a sub model is developed with refined mesh. Force and displacement boundary conditions are transported from the global model. Interlaminar stresses and shear stress distributions at the core and girder are then determined. Materials failure criteria for composites and foam are applied on the sub model and structural integrity of each component is checked. An analysis without FSI is also performed on a reference model with identical load and boundary conditions and the result is compared with that of FSI.