Structural similitude design for a scaled composite wing box based on optimised stacking sequence

Abstract

Testing appropriately-designed scaled-down structures instead of the full-size prototype structure is beneficial for quickly understanding the prototype structural behaviour in a cost-effective way. In this study, a novel approach is proposed to design scaled composite structures that can be used to predict the structural responses (e.g. static bending, modal behaviour, and compressive buckling) of the prototype. The objective is to overcome the main drawback of the conventional design method, which tends to result in low accuracy of the prototype prediction when certain variables cannot be appropriately scaled due to manufacturing constraints (e.g. ply thickness). In the present work, a set of scaling laws being independent of boundary conditions were firstly derived for plates and beams respectively based on their governing equations. The genetic algorithm (GA) was then applied to help design the stacking sequence of the scaled models, accommodating the mismatch in similarity conditions resulting from the manufacturing constraint in ply thickness. This GA-based design method was demonstrated to be effective in designing scaled plate, I-beam, and stiffened plate models, with improved accuracy in predicting the prototype structural behaviour compared with the conventional method. The application of this new design method was also extended to an A320 size wing box structure, validating its robustness for complex structures.

Towards Structural and Aeroelastic Similarity in Scaled Wing Models: Development of an Aeroelastic Optimization Framework

“…The results in terms of aerodynamics, structural dynamics as well as the nonlinear aeroelastic response of the scaled models were compared with the one estimated for the full-size model. The prevalence of composite materials in the aeronautics scene also led the scientific community towards the exploration of aeroelastic scaling frameworks of composite materials wings [6,18]. More recently, an MDO methodology for aeroelastic scaling without similar flow conditions was proposed in [19] .…”

Similitudes for vibration characteristic of composite laminated plates

“…The governing equation of laminated plate is given by You et al (2019)where the coefficients D ij represent the flexibility rigidity of the plate, w represents the displacement along the z -direction at the point ( x , y ), ρ is the density of the material, and h is its thickness.…”

“…You et al (2019) proposed a novel approach to design scaled composite structures by applying the genetic algorithm (GA) that can be used to predict the structural responses (e.g., static bending, modal behavior, and compressive buckling) of a composite wing box. It is an interesting work involving the vibration characteristic of complex structures.…”

“…In a comprehensive review, Casaburo stated that new methods should try to face the resolution of more complex problems, such as applications to acoustic-elastic systems or structures made of several components (Casaburo et al, 2016). You et al (2019) proposed a novel approach to design scaled composite structures by applying the genetic algorithm (GA) that can be used to predict the structural responses (e.g., static bending, modal behavior, and compressive buckling) of a composite wing box. It is an interesting work involving the vibration characteristic of complex structures.…”

Similitude for the Dynamic Characteristics of Dual-Rotor System with Bolted Joints

“…Aiming at coupled structures, De Rosa and Franco predicted the vibration responses of assemblies of plates [23], coupling beams and plates [24], and long and short wavelength coupling structures [25]. You et al [26] presented a scaling procedure for wing boxes and put the deflection and modal behavior into similitude. Song et al [27] investigated the similitude of machine tools, and then the modal shape was predicted by the scaled model.…”