Study of Composites Ducts for Optimal Design of an Horizontal Axis Tidal Turbine

To satisfy the requirements of tidal turbines manufacturers which are mostly linked to mass reduction, composite materials present a considerable compromise due to their excellent «mass/strength» and «mass/stiffness» ratios. Design of ducted tidal turbine involving a compromise between hydrodynamic efficiency and structural strength was investigated in this research project. Therefore, structural design of the composite duct providing the best ratio «Power/Mass» was obtained. The duct structure is particularly subjected to accidental impact loads due to its position surrounding the rotor. The damage induced by the accidental impact was investigated in detail in this research project. A 3D mesoscale damage model combining intralaminar model based on bilinear law (damage onset and softening) and interface bilinear damage model (CZM) was developed and linked into Abaqus/Explicit FEM software. The 3D damage model was validated through experimental impact test data of composite tubular structures intended for underwater application. The developed damage model was then applied to the certification of various structural parts of the composite duct.