On the Motion of the Aircraft under Alternate Wing Pressure Loading

Abstract

An aircraft structure is considered freely in air, unsupported. It is discretized with a set of triangular shell finite elements. It is subjected to alternate pressure forces on its wings. The governing equation is the nonlinear dynamics equation, the nonlinearity arising from the inclusion of the geometrical stiffness allowing for large displacements. The time dependent nonlinear problem is solved by a finite difference scheme. Time-displacement curves are given for a point on the tip of the wing and on the body shell. Under alternate pressure forces -as in case of turbulence- the wings displace upwards in a nonlinear way and then rigid body motion of the aircraft takes place. The motion has chaotic characteristics.