Benefits from Thin-Ply Composite Materials in Aircraft Wing Structures

Abstract

Previous research shows that thin-ply composite materials offer superior static and fatigue characteristics to standard laminates used in aviation. Therefore, they are expected to be capable of significantly contributing to a mass reduction needed to improve the energy-efficiency of future aircraft. However, so far, thin-ply composites have only been employed in special applications. Quantitative full-scale assessments of the benefits on the level of global aircraft structures are missing. This study employs a parametric, finite element-based tool chain with a fully-stressed design methodology to investigate potential benefits from the use of thin plies, which may result from increased strength, an extended design freedom and stability considerations, in a generic wing structure of a conceptual medium-range aircraft in order to reduce this research gap. The methodology is validated using an academic test case. Naturally, mass reductions from strength enhancements are limited by buckling constraints in thin-walled structures. However, for the wing examined in this study, an increase in strength of 10 still yields up to a 7.9 reduction in global wing mass, while an increase of 20 results in mass savings of up to 13.4. The use of thin-ply composites may allow for reducing minimum wall thickness constraints. Associated mass savings of up to 3.1 found in this study on global wing level when alleviating the requirement from 2.4mm to 1.2mm are, however, restricted to rib mass and may better be achieved by different means such as topology optimisation. In contrast, mass penalties from the application of a simplified manufacturing constraint are reduced significantly from beyond 10 on global wing level for plies with a thickness of 0.175mm to approximately 1.5 with a ply thickness of 0.05mm.