Static shape control for adaptive wings

Abstract

A theoretical method was developed, and experimentally validated, to control the static shape of flexible struc-tures by employing internal translational actuators. A finite element model of the structure, without the actuatorspresent, is employed to obtain the multiple-input, multiple-output control-system gain matrices for actuator-loadcontrol as well as actuator-displacement control. The method is applied to the quasistatic problem of maintainingan optimum-wing cross section during various transonic-cruise flight conditions to obtain significant reductionsin the shock-induced drag. Only small, potentially achievable, adaptive modifications to the profile are required.The adaptive-wing concept employs actuators as truss elements of active ribs to reshape the wing cross section bydeforming the structure. Finite element analyses of an adaptive-rib model verify the controlled-structure theory.Experiments on the model were conducted, and arbitrarily selected deformed shapes were accurately achieved.