Structural Optimization Design of a Skateboard Chassis Based on Universal Kriging–NSGA-II–TOPSIS

To achieve coordinated optimization of lightweighting and static–dynamic performance for a skateboard chassis, this paper proposes a multi-objective optimization method based on Universal Kriging, NSGA-II, and TOPSIS. A three-dimensional parametric model of the skateboard chassis structure for electric commercial vehicles was established based on a modular design philosophy, and modal and static analyses under four typical operating conditions were conducted. Six key variables were identified through parameter sensitivity analysis, and a surrogate model was constructed using the optimal Latin hypercube sampling method and the Universal Kriging model. The NSGA-II algorithm was used to solve the multi-objective optimization model and obtain a set of Pareto optimal solutions, from which the optimal compromise solution was selected using the entropy-weighted TOPSIS multi-criteria decision-making method. The optimized design achieved the objectives of reducing the skateboard chassis mass by 2.02%, decreasing the maximum deformation under bending conditions by 19.16%, and increasing the first-order natural frequency by 2.24%, thereby effectively improving lightweight, stiffness, and dynamic response performance of the skateboard chassis. This method integrates modular design with multi-objective optimization, providing a theoretical framework and technical pathway for the structural optimization design of a skateboard chassis.