基于拓扑优化与6σ稳健性的检修工装支撑座轻量化设计

LIGHTWEIGHT DESIGN FOR OVERHAUL TOOLING SUPPORT SEAT BASED ON TOPOLOGY OPTIMIZATION AND SIX SIGMA ROBUSTNESS

为了充分发挥踏面制动单元(TBU)检修工装支撑座的轻量化潜力和提高优化设计的可靠性与稳健性,提出将拓扑优化与6σ稳健性优化相结合的优化策略。通过基于变密度法的拓扑优化设计,提取支撑座的拓扑结构。基于中心组合试验设计方法和有限元数值模拟技术建立系统的响应面模型。基于该模型建立支撑座的6σ稳健性优化设计模型,并采用序列二次规划法进行优化求解,利用均值一次二阶矩法获得优化结果的可靠度并转化为相应的σ水平。结果表明,优化后的支撑座各设计变量、强度和刚度的可靠度均为1,均达到了8σ水平,减重率达67. 0%,轻量化效果显著;且与拓扑优化后对其进行传统的确定性轻量化设计相比,该方法不仅使支撑座的强度和刚度得到了增强,而且还提高了优化设计的可靠性、强度与刚度的稳健性和重量的一致性。证明了该方法的有效性。

In order to give full play to the lightweight potential of the tread braking unit( TBU) overhaul tooling support seat and improve the reliability and robustness of the optimization design,an optimization strategy composed of topology optimization and 6σrobustness optimization was proposed. Support seat’s topology structures was extracted based on topology optimization with variable density method. The response surface model was established based on the central composite design method and the finite element numerical simulation technique. The support seat’s 6σ robustness optimization design model was established based on this model. The sequential quadratic programming method was adopted to solve this optimization problem.The reliabilities of the optimization results were obtained with the mean value first order and second moment method,and were transformed into corresponding σlevels. The results show that reliability of the design variables,strength and stiffness are all 1,reaching eight sigma level,the support seat’s weight is reduced by 67. 0% and the lightweight effect is remarkable;compared with the support seat’s traditional deterministic optimization design after topology optimization,this method enhances the strength and stiffness of the support seat,meanwhile,improves the reliability of the optimization design,the robustness of the strength,the robustness of the stiffness and the consistency of the weight. So the proposed optimization strategy is proved to be efficient.