Parameter Sensitivity Analysis and Optimization Design of Air Rudder Cell Structures Under Thermo-Mechanical Coupling

Lightweight sandwich structures offer significant deformation resistance under extreme thermo-mechanical conditions, thereby enhancing the structural stability of air rudders. This study focuses on the cell units within an air rudder sandwich panel. This study investigates the parameter sensitivity and optimization of a sector-shaped sandwich cell featuring radial and circumferential ribs. A Radial Basis Function (RBF) surrogate model is constructed based on an Optimal Latin Hypercube Sampling (OLHS) dataset, and a Pointer auto-optimizer is employed to minimize mass under deformation constraints. The input parameters are standardized using Z-score normalization, and a linear regression model including main and interaction terms is developed to assess key sensitivities. Results reveal that the radial rib number (n1) is the dominant factor affecting total elastic strain energy and maximum deformation. Strong coupling effects are identified in the interactions between radial and circumferential rib numbers (n1×n2), and between radial rib number and skin thickness (n1×b4), with n1×n2 showing pronounced sensitivity to temperature gradients. Under four constraint conditions targeting the minimization of global and local deformation, the optimized cell structures achieved reductions of 88.17%–70.79% and 81.08%–69.41%, respectively. However, the effectiveness declines as skin thickness increases. Validation results confirm these findings, showing decreases in global and local deformation of 16.41%–12.86% and 3.56%–2.65%, respectively.