Effect of skin and spar laminate orientations on flutter of composite uav wing

Abstract

This paper presents an analytical study on the optimisation of composite laminate orientation lay-up to achieve the maximum flutter with minimum weight penalty. The study is carried out by using UTM CAMAR UAV swept back wing as a case study where the wing consists of two spars located at 35% and 55% of the wing chord length. The laminate lay-up of the spar and the wing skin are optimised by considering different variations of laminate ply orientation while the number of plies for each part are set to be constant throughout the work. The finite element analysis software, Abaqus, was used to obtain the structural natural frequencies for bending and torsion modes. The bending stiffness, torsion stiffness and the eigenvalues of the aeroelasticity equation of motion are computed using the mathematical software, MATLAB. The maximum flutter speed obtained from the study is 238.93 m/s with laminate configuration at [45°/-45°/45°/-45°] for wing skin, [45°/-45°/45°] for forward spar, [45°/-45°]s for aft spar and [0°/0°/0°/0°] for the wing tip.