Tail gate lightweight of mini bus based on robustness and multi objective optimization
YUAN Ting hui, NI Shi lin, WANG Xiao, LIU Hui xia
(School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China)

Abstract: Aiming at the problem of lightweight design for the tail gate structure on mini bus, a method based on 6σ robustness analysis and multi objective optimization was presented. Firstly, the sensitivity analysis was used to pick out tail gate parts contributing more to tail gate performance as the design variables, and then the approximate models of each working condition response of tail gate were established. Secondly, taking tail gate torsion stiffness, drooping stiffness, the first three modal frequency, and dent resistance as the constrains, taking the minimum mass, maximum first modal frequency and minimum bending stiffness displacement of tail gate as targets, the multi objective optimization was conducted by using the NSGA Ⅱ, then the 6σ quality level analysis and robustness multi objective optimization were carried out by using Monte Carlo simulation. The results indicate that under the requirements of all performance, the mass of tail gate is reduced by 2.28 kg and the bending stiffness and first modal frequency are improved. At the same time, the robustness of each working condition performance of the tail gate structure is also improved，reaching 6σ quality level.

Key words: tail gate; lightweight; multi objective optimization; 6σ robustness