Influence of Fiber Orientation and Material Anisotropy in Hydroelastic Response of Laminated Composite Cycloidal Propeller Blade

Composite materials are increasingly favored propellers, hydrofoils, waterjets, and other marine vessel components for their high stiffness-to-weight ratios and anisotropic properties. The fiber orientation of laminates significantly influences the stiffness of the blade. This study investigates the hydrodynamic loading and structural behavior of laminated composite marine cycloidal propeller (MCP) blades during zig-zag (ZZ) and turning-circle (TC) maneuvers. Composite materials such as carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP), with uni-directional (UD), bidirectional (BD), and cross-ply (CP) fiber orientations, are considered. A matlab code is developed for the 3D boundary element method (BEM) to compute hydrodynamic loads acting on and the nonlinear finite element method (FEM) to calculate the structural responses of the MCP blade. UD and BD fiber orientations are optimized for the MCP blade by performing static analysis in air through minimizing deformation, twist, and the Tsai–Hill failure index. Hydroelastic responses such as deformation, velocity, twist angle, and stress of the MCP blade are analyzed during ZZ and TC maneuvers. The results show that the UD exhibits higher bending stiffness and the BD exhibits higher torsional stiffness. The CFRP blades show better structural performance compared to GFRP. However, both materials show sufficient structural integrity with a failure index (FI) of less than one during ZZ and TC maneuvers. This study highlights the potential of composite material as a viable alternative to the metallic blade in ship propulsion systems.