Effect of Free-Play and Initial Conditions on Aeroelastic Behavior of a Missile Canard in Supersonic Flow

Abstract

Canards are used as control surfaces and they operate with control systems including actuators, drivelines and electronics in missiles. Aeroelastic behavior of the canards must be accurately known to comply with the control systems. However, structural nonlinearities such as plastic deformation, bilinear stiffness and free-play change the aeroelastic characteristics of the structure. This study aims to illustrate nonlinear aeroelastic behavior of a missile canard which has free-play in its shaft-actuator joint. Three initial angle of attack positions and two different free-play sizes were evaluated with fluid-structure interaction (FSI) method. Nonlinear behavior of the canard was compared with the linear, which has no free-play, condition. Consequently, FSI results showed that response frequencies decrease as free-play increases and amplitudes of oscillations are affected by initial conditions.