An Efficient Hybrid Structural Optimization Design Method for Bolt-Connected Stiffened Panels

To address the modeling complexity and large computational load in optimizing the buckling performance of bolted stiffened panels, a hybrid optimization strategy based on the Kriging surrogate model and the multi-point constraint (MPC) approximation model was proposed. Firstly, the MPC connection was utilized to establish an approximate stiffened panel model for the finite element buckling analysis, to replace the analysis of many high-precision stiffened panel models in the experimental design. Then, a prediction function for MPC parameters was built with the Kriging surrogate model, and the sample points of the surrogate model were updated during optimization iterations to ensure the computational accuracy of the approximation model. Finally, based on the established MPC approximation model, the lightweight design and the performance optimization design of bolted stiffened panels were conducted. The numerical results demonstrate that, the proposed hybrid optimization method improves the computational efficiency by approximate 10 times compared with traditional optimization methods. In the lightweight design, the weight of the stiffened panel structure reduces by 26.18% while maintaining the same buckling capacity. In the performance optimization design, the ultimate buckling capacity increases by 23.67%.without significant change in the structural mass.