Stability Analysis of a Subsonic Aircraft with Flight Control System Including Structural Damage

This paper aims to study a modeling technique for flutter analysis of subsonic aircraft by using finite element analysis including flight control failures. By applying distribution of stiffness of dynamic characteristics model as a beam element and distribution of mass as a concentrated mass, the configuration of aircraft idealized. The aerodynamic force model includes all lifting surfaces, fuselage and utilized doublet lattice method in consideration of mutual interference effect between lifting surface and lifting face and lifting surface and fuselage, in empty fuel condition, to 1.74 Vd and in full fuel condition, to 1.71 Vd. There has been no aeroelastic instability on the subsonic aircraft. As a result of flutter analysis based on hinge damage of control surface, it has been proved that it is safe to damages. However, it is required to observe carefully whether the hinge of rudder has been damaged, since the flutter seed decreases significantly when there is one. The control system that has major impact on the aeroelastic characteristic of subsonic aircraft has been modelled to represent the rotational mode of rigid body and elasticity. The flutter analysis has been conducted on empty fuel condition, full fuel condition, changes in volume of mass balance, cases of hinge damage and its results.