Abstract: According to the structure characteristics of the rudder and molding process of composite materials, four composite rudder schemes were designed to improve the joint strength between the metal frame and composite skin. Then the 3D finite element (FE) model was established to analyze the static strength of each rudder scheme. Finally, the optimal scheme by adding the gasket and rivets at the junction between the composite skin and metal skeleton was determined. Based on this scheme, the composite rudder was fabricated by resin transfer mould (RTM) process. The room temperature static strength test and thermo-mechanical test under bending load were completed. The analysis results show that the stress of the resin junctional area and skeleton is reduced greatly when the skeleton and skin root are strengthened by adding gaskets and adhesive bolted joint, which improves the bearing capacity of the composite rudder significantly. The experimental results show that the composite rudder has no residual deformation under 150% of the service load at room temperature static strength test. Meanwhile, the rudder maintains the structural integrity and meets the structural design requirements under combined high temperature and load, which verifies the feasibility of the design scheme.

Key words: composite, rudder, thermo-mechanical coupling test, finite element analysis