Abstract
The aim of the paper is to experimentally validate a numerical design methodology for optimizing composite wings subject to gust and fatigue loading requirements and to assess the effect of fatigue on the aeroelastic performance of the wing. Traditionally, to account for fatigue in composite design, a knockdown factor on the maximum stress allowable is applied, resulting in a conservative design. In the current design methodology, an analytical fatigue model is used to reduce the conservativeness and exploit the potential of composite materials. To validate the proposed analytical model, a rectangular composite wing is designed and manufactured to be critical in strength, buckling and fatigue. An experimental campaign comprising wind tunnel and fatigue tests is performed. In the wind tunnel, both static and dynamic aeroelastic experiments are conducted to validate the numerical dynamic aeroelastic model. The fatigue test is used to validate the analytical fatigue model and to understand the effect of fatigue on aeroelastic properties of the wings. The results from experimental campaign validated both the aeroelastic predictions as well as fatigue predictions of the numerical design methodology. However the fatigue process resulted in degradation of the wing stiffness leading to change in the aeroelastic response of the wing.
Highlights
Composite materials with their high specific strength are becoming a preferred choice for an efficient aircraft structure
The current paper extends the work done by Werter et al [10] by first designing and manufacturing a composite wing with an actual wing box, which includes ribs and spars such that there are clear load carrying paths; second, by testing under gust loading conditions, and third by performing fatigue tests on it
The experimental campaign consisted of two wind tunnel tests and one fatigue test
Summary
Composite materials with their high specific strength are becoming a preferred choice for an efficient aircraft structure. There has been a lot of work on the application of composite materials to aeroelastically tailor the aircraft wings with an objective of minimizing the structural weight [1,2,3,4,5,6]. As the wings become more optimized for improved aeroelastic behavior, unsteady gust loads start to size the structure along with the static load cases [8]. After every iteration, there is an update in the design which changes the aeroelastic properties of the wing leading to a change in critical gust load. The authors [8] in their previous work have developed a methodology to include critical gust loads efficiently in the aeroelastic optimization of composite wings using the TU Delft in–house preliminary aeroelastic design tool PROTEUS [10]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call