Geometric Optimisation of Hinge-Less Deployment System for an Active Rotorblade

The Green Rotorcraft project (part of Clean Sky JTI) is studying the Gurney flap as a demonstrator of a smart adaptive rotorblade. Deployment systems for the Gurney flap need to sustain large centrifugal loads and vibrations while maintaining precisely the displacement under aerodynamic loading. Designing such a mechanism relies on both the actuation technology and the link which transmits motion to the control surface. Flexible beams and piezoelectric patch actuators have been chosen as components to design this mechanism. Flexible beams are providing an hinge-less robust structure onto which the piezoelectric actuators are bonded. A candidate topology is determined by investigating the compliance of a simple wire structure with beam elements. A parametrized finite element model is then built and optimized for displacement and force through surrogate optimization. The whole process does not requires many finite element analyses and quickly converge to an optimized mechanism.