Structure analysis and aeroelastic optimization method for composite wing-box structure with curved fiber

Composite structure has significant weight advantages and has been widely used for modern aircraft structures as well as other structure design with high strength, high stiffness and light weight requirements. Traditional composite laminates with straight fiber are susceptible to instability failure when subjected to in-plane compression and shear loads, hence the potential advantages of composite laminates are not fully utilized during use. The variable angle tow (VAT) fiber composite is less restricted in design and manufacturing compared with straight fiber composite laminates, which greatly improves design space and therefore the advantages of weight reduction are obvious. A modeling method for composite wing-box structure with cureved fiber laminates is proposed, baesed on which a structure optimization framework is established considering multidisciplinary constrains including buckling, static aeroelastic deformation and flutte. The optimization strategy of straight fiber laminates composite is not suitable for curved fiber laminates, therefore a novel optimization strategy is proposed to achieve optimal design of cureved fiber lanimate wingbox. In addition, the manufacture constraint for tow streed fiber dropping is alos taken into consideration to ensure the rationality of optimal design.