Smart Passive Adaptive Control of Composite Plates
Start date: 12 November 2010
Generally two different rotations occur by applying simple bending on a composite plate with different fibre orientation angles. The main rotation takes place in the force direction and causes the bending of the composite plate. There is also another small rotation which causes the twist of the composite plate.
In this paper, a laminate layup configuration methodology is implemented for multidirectional fibre composite laminates to achieve desirable induced twist angles in simple bending. In classical laminate theory, it is assumed that the laminate is thin compared to its lateral dimensions and straight lines normal to the middle surface remain straight and normal to the surface after deformation. The transverse shear stresses and shear strains are ignored hence the rotation will disappear. In previous published research this twist is assumed to be an unwanted displacement and for simplicity it was ignored. However, in certain cases this twist is not redundant and can be a useful displacement to passively control the behaviour of the composite. This has potential applications in, for example, wind turbine blade design by enabling smart passive adaptive control to improve efficiency.
In this study, by applying the transverse shear stresses and shear strains, the influence of twisting angles are presented and discussed for different cases and different fibre orientation layups. By considering a fixed thickness of the composite plate, the optimum fibre orientation angle is investigated and proposed for each layer in order to produce the desirable twist angle.