Modified multilevel layout optimization method of composite wing structure

A three level layout optimization strategy is proposed in this paper for large-scale composite wing structures. Design requirements are adjusted at the primary level according to structural deformation and strength, then the stringers and ribs layout are designed by the instability criteria at the second level, at last the laminate optimization is used to increase the composite panel carrying efficiency. In this paper, stiffened wing panels first are modeled by the equivalent laminate plates, whose thickness is determined by the global wing structure's deformation and strength. At last a detailed FEM model is build to reflect accurate instability limit and is used to do global synthetical optimization. Finally, the three level optimization of large-scale wing structure is completed as an example. The result fulfills design requirements and shows the feasibility of this method.