Simultaneous size, layout and topology optimization of stiffened panels under buckling constraints

This study investigates the weight minimization of stiffened panels simultaneously optimizing size, layout and topology under buckling constraints. An effective topology optimization parameterization is proposed. Specifically, the stiffened panel is discretized into plate elements. A control mesh is developed to manipulate the stiffener layout, and a free-form mesh deformation method is utilized to adjust the finite element mesh. The level set method is used to optimize the internal topologies of the stiffeners, and sizing design is also included, optimizing the thicknesses of the panel and stiffeners. To solve the optimization problem, a semi-analytical sensitivity analysis is performed, and the optimization algorithm is outlined. Numerical investigations demonstrate the effectiveness of the proposed method