Configuration of a shear web based actuation system

Abstract

Shape adaptive systems and structural configurations are necessary to fulfil the demands of a future unmanned aerial vehicle structure. Predominantly the present approaches are based on a passive load-bearing structure having smart actuation systems deforming the passive structural configuration elastically in the wanted shape. Therefore the actuation system can be based on discrete actuators, like electrically driven motors using gearing systems to transform the displacement into the structure or on smart material configurations places on the load bearing passive structure, deforming the structure within the elastic region into the wanted shape. This is a successful approach for certain applications, e.g. smart rotor blade. Using smart materials within load-bearing structures, elastic and static strength properties vary between passive and active structures. Matching these properties is a great challenge for future structural configurations. The availability of two-dimensional smart actuator configurations with distinct actuation orientation allows the definition of a distinct load bearing active structure. Therefore the so called "web" of a spar-equivalent configuration was substituted by such a smart material actuator also known as macro fibre composite (MFC). Activating the web of the active cantilevered spar-configuration is resulting in a free end displacement. The main advantage lies in the fact that the active displacement will be load independent and, compared to a passive structural configuration with applied smart material actuators, larger. Within the paper the process of developing the shear web based actuation system with configuration details will be illustrated and future steps will be proposed.