Active Twist Performance for Optimal Design of Helicopter Rotor Blade with D-spar
Proceedings of the 4th International Conference Strength, Durability and Stability of Materials and Structures 2007
Andrejs Kovaļovs, Jevgenijs Barkanovs, Sergejs Gluhih

Vibration of helicopter have different sources, such as the rotor, engine and transmission system. This problem create a lot of disadvantage with performance of helicopters, maneuverability, discomfort of pilot, low fatigue life of the structural components, and consequently high operating cost. Present time exist various methodologies for vibration reduction, such as Higher Harmonic Control (HHC), Individual Blade Control (IBC), Active Control of Structural Response (ACSR) , Active Twist Blade (ATB), and Active Trailing-edge Flap (ATF). The goal of the presented work is the development of an active twist actuation concept, which based on application of Macro Fiber Composite (MFC) actuator. These actuators consist of polyimid films with IDE-electrodes that are glued on the top and the bottom of piezoceramic ribbons and oriented at ±450 to blade spanwise axis. The interdigitated electrodes deliver the electric field required to activate the piezoelectric effect in the fibers and allows to invoke the stronger longitudinal piezoelectric effect along the length of the fibers. Due to properties and orientation of piezoelectric actuators the MFC actuators to induce shear stresses and thus a distribute twisting moment along the blade. The design methodology based on the planning of experiments and response surface technique has been developed for an optimum placement of Macro Fiber Composite (MFC) actuators in the helicopter rotor blades. Two different designs of the active material application have been studied to determine their effectiveness: one active plie in top of skin and two plies in top and bottom of skin. The baseline helicopter rotor blade consists of D-spar made of unidirectional glass-fiber reinforced plastic (UD GFRP), skin made of ±450 GFRP, foam core, MFC actuators placement on the skin and balance weight. 3D finite element model of the rotor blade has been built by ANSYS, where the rotor blade skin and spar “moustaches” are modelled by the linear layered structural shell elements SHELL99, and the spar and foam - by 3D 20-node structural solid elements SOLID186. The thermal analysis of 3D finite element model have been developed to investigate an active twist of the helicopter rotor blade. Strain analogy between piezoelectric strains and thermally induced strains is used to model piezoelectric effects. The optimisation results have been obtained for design solutions, connected with an application of active materials, and checked by the finite element calculations.


Keywords
active twist, Macro Fiber Composite (MFC), helicopter rotor blade, optimisation.

Kovaļovs, A., Barkanovs, J., Gluhih, S. Active Twist Performance for Optimal Design of Helicopter Rotor Blade with D-spar. In: Proceedings of the 4th International Conference Strength, Durability and Stability of Materials and Structures, Lithuania, Palanga, 11-13 September, 2007. Palanga: KTU, 2007, pp.53-59.

Publication language
English (en)
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