Citation:
S J Guo, J R Bannerjee, C W Cheung. The effect of laminate lay-up on the flutter
speed of composite wings . Proceedings of the Institution of Mechanical
Engineers, Part G: Journal of Aerospace Engineering, Volume 217, Number 3 (June)
2003, pp115-122.
Abstract:
This paper presents an analytical study on optimization of a laminated composite
wing structure for achieving a maximum flutter speed and a minimum weight
without strength penalty. The investigation is carried out within the range of
incompressible airflow and subsonic speed. In the first stage of the
optimization, attention has been paid mainly to the effect on flutter speed of
the bending, torsion and, more importantly, the bending-torsional coupling
rigidity, which is usually associated with asymmetric laminate lay-up. The study
has shown that the torsional rigidity plays a dominant role, while the coupling
rigidity has also quite a significant effect on the flutter speed. In the second
stage of the optimization, attention has been paid to the weight and laminate
strength of the wing structure, which is affected by the variation in laminate
lay-up in the first stage. Results from a thin-walled wing box made of laminated
composite material show that up to 18 per cent increase in flutter speed and 13
per cent reduction in weight can be achieved without compromising the strength.
The investigation has shown that a careful choice of initial lay-up and design
variables leads to a desirable bending, torsional and coupling rigidities, with
the provision of an efficient approach when achieving a maximum flutter speed
with a minimum mass of a composite wing.