Structural Design and Analysis of a 3D Fabric-Reinforced Composite Outlet Guide Vane

Sammanfattning

History shows that commercial airline engines have become larger and heavier. Dueto the close relation between engine weight and fuel efficiency, a weight reductionwould reduce aviation’s carbon footprint. The introduction of composite materials,in particular those with carbon fibre reinforcements, to replace traditional metallicalloys is one avenue to create lighter aeroengines.This work focuses on an innovative class of composite material with 3D fabricreinforcement.By having fabric-reinforcement in three dimensions one can overcomea number of challenges found in traditional laminated composite, such as theirsusceptibility for delamination and poor out-of-plane properties.The aim of this study is to clarify the mechanical and thermal properties of 3D fabricreinforcedcomposite materials across different scales. This is in order to propose afinal suitable 3D orthogonal non-woven yarn architecture for an Outlet Guide Vane(OGV) in an aero engine. Firstly, the microscale characteristics of these materialsare examined, considering the combination of an epoxy matrix and carbon fibres,to provide insights into their mechanical and thermal behaviour. Subsequently,this thesis delves into the mesoscale, integrating micro-mechanical properties of theyarns and polymer matrix properties to tailor the fibre distribution within the yarnstructure, aiming to meet the failure criteria on the macroscale. Moreover, it investigatesthe hypothesis that off-axis yarns enhance shear stiffness moduli, utilisingmodelling and simulation techniques. Through simulations on the macroscale, thestudy validates the mechanical elastic properties of the composite material, ensuringits adequacy for the prescribed failure criteria. Furthermore, it predicts andanalyses heat transfer effects across the orthogonal non-woven yarn structure whenembedded with a thermal element, leveraging calculated thermal properties. Lastly,informed by findings on the macroscale, a final composite yarn structure is proposedthat is suitable for application in the designated OGV context. This comprehensiveinvestigation contributes to advancing the understanding of composite materials,particularly in aerospace applications.