Aeroelastic Tailoring of High Aspect Ratio Cantilever Wings

Abstract

High aspect ratio wings, integral to enhanced flight performance and extended endurance due to their role in reducing drag, present challenges owing to their flexibility and susceptibility to aeroelastic instabilities. This research delves into passive aeroelastic tailoring, a design-phase approach aimed at optimizing aeroelastic performance while balancing cost and weight constraints. The cornerstone of this tailoring method lies in the strategic use of composites, renowned for their high strength-to-weight ratio compared to traditional isotropic materials like Aluminium. Beyond materials, the research also explores novel structural layouts for aeroelastic tailoring, through alterations in the angular arrangement of the internal wing structures. These methodologies alter the bend-twist and the shear-extension couplings of wings, thereby enhancing aeroelastic instabilities by reducing gust-induced root bending moments and root shear forces and minimizing wing stress. Nevertheless, aeroelastic instability may also be delayed, thus, expanding the flight envelope and ensuring safe operations.
The focus of this research initially centres on the application of aeroelastic tailoring methodologies to a cantilevered stiffened flat plate. By targeting such a fundamental structure as the cantilevered stiffened flat plate at the outset, this study aims to establish foundational insights and methodologies that can be extrapolated to more complex aeronautical structures. Findings suggested that significant aeroelastic tailoring can be achieved using forward swept stringers and varying the ply orientation of the plate. Progressing to complex wing geometries, the research expands its scope to intricately combine both geometric and material tailoring methods. Challenges due to the wing structure complexity include maintaining the total mass and avoiding the alteration of unfavourable couplings created by either the material or rearranging the internal wing structure. In essence, this research offers a comprehensive exploration of aeroelastic tailoring, fusing the principles of geometry and advanced material.

Date of Award	11 Dec 2023
Original language	American English
Supervisor	Rafic Ajaj (Supervisor)