Re-design of a helicopter component transmission by composite material

The aim of this paper is to present an innovative application of composite materials by resin transfer moulding (RTM) technology for a helicopter component transmission traditionally made by metallic materials. This task requires a structural analysis performed simultaneously with an appropriate tooling design and the investigation of the material processability. In this work we present the structural optimization design for a component to be manufactured with braided preform, as well as a study of permeability and selection of resins. The purpose of the structural design was to minimize the weight of the structure through reduction of the total thickness with preservation or improvement of the mechanical performances. A simplified finite element model was adopted to obtain the distribution of thickness along the conical profile. In order to study the relationship between braided angle and permeability parallel to the mandrel axis, several experiments was conducted at different braided angles for some of thicknesses. This will be necessary to evaluate the best strategy of an injection scheme. The processability of a selected set of resins for aerospace RTM applications was carried out. The materials were chosen in order to guarantee the high mechanical, physical and thermal performance of the component in exam.