On the aeroelasticity of high aspect ratio strut-braced wings: A parametric study

ifasd2024 Tracking Number 100

The aviation industry is increasingly adopting high aspect ratio (AR) wings to meet the demands for more efficient and emission-friendly aircraft. High AR wings increase aerodynamic efficiency but come at the cost of structural and aeroelastic issues [1]. A candidate solution for these aeroelastic issues is strut-bracing. For example, the Boeing Sugar VOLT (AR = 19.55 [1]) utilizes strut-bracing at approximately 50% of the span and 15% of the chord[2]. This paper conducts a comprehensive parametric study on a high aspect-ratio (AR = 16) strut-braced flat plate (shown in figure 1) to identify the influence of material and geometric parameters on structural performance and aeroelastic stability. The finite element method is used for structural modelling, the doublet lattice method for aerodynamic modelling, and an infinite plate spline for aero-structural coupling. The analysis is conducted using MSC Nastran and MATLAB. The geometric variables include the location of the strut on the plate, the location of the strut on the fuselage, and boundary conditions on strut ends. The material of the plate is then changed from Aluminum-2024 to Carbon Fibre Reinforced Plastic composite, and the ply orientation and layup are also varied. The location of the strut on the plate is varied chordwise and spanwise, while the location of the strut on the fuselage is either fixed at mid-chord or variable with the location of the strut on the wing. The boundary conditions on the strut end (fuselage-wing) are varied between clamped and pinned (4 combinations). The optimum geometric parameters for the metal plate are found to be clamped-integral boundary conditions, with the variable location on the fuselage. The optimum geometric parameters are applied to the composite plate, and the ply orientation and strut location on the plate are studied. The optimum has a ply layup of [0, −45◦]s, and a strut location at 20-30% of the span, and 30-50% of the chord. This results in a 37% increase in the critical speed, a 71.5% decrease in the max bending moment and 21.35% decrease in shear forces.