VIBRATION ANALYSIS OF COMPOSITE WING WITH TIP MASS USING FINITE-ELEMENTS

Abstract

The analysis of vibration characteristics, including the natural frequencies and modes for various shaped composite wings with a tip mass and an engine, has been performed using the finite element method based on the shear deformable theory. The present analysis presents the effect of tip mass, engine, sweep angle, fiber orientation and aspect ratio of a composite wing, which is composed of graphite/epoxy laminate with a symmetric stacking sequence, on vibration characteristics. At a specific fiber orientation, the natural frequencies of the two modes approach each other. The natural frequencies of the wing with the tip mass and the engine are lower than those of the wing without the tip mass and the engine. However, for the wing with the tip mass, the natural frequencies of the chordwise mode increase due to the increase of the bending stiffness of the tip mass. This present finite element method, which uses eight-node quadrilateral elements, gives very accurate results.