基于双层更新Kriging模型的机械结构动态特性稳健优化设计  

Robust Optimization for Dynamic Characteristics of Mechanical Structures Based on Double Renewal Kriging Model

作　　者：李小刚[1] 程锦[1] 刘振宇[2] 吴震宇[1] 

机构地区：[1]浙江大学流体动力与机电系统国家重点实验室,杭州310027 [2]浙江大学CAD&CG国家重点实验室,杭州310058

出　　处：《机械工程学报》2014年第3期165-173,共9页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51275459);国家重点基础研究发展计划(973计划;2011CB706503);国家科技重大专项(SK201201A28-01);中央高校基本科研业务费专项资金(2013QNA4005)资助项目

摘　　要：针对现有机械结构优化设计未考虑材料特性参数的不确定性和结构动态特性对综合性能的影响、优化求解效率低下等不足,提出基于双层更新Kriging模型的机械结构动态特性稳健优化设计方法。将机械结构动态特性指标的均值和方差作为优化目标,将机械结构变形量作为约束条件,建立机械结构动态特性稳健优化的数学模型。利用拉丁超立方试验设计、误差最大区域和近似最优解邻域的局部样本点加密技术和双层更新策略,建立能准确高效地获取稳健优化目标和约束函数值的Kriging模型。在此基础上,基于邻域培植遗传算法和双层更新的Kriging模型求出机械结构动态特性稳健优化问题的所有Pareto最优解。某型号大型汽轮发电机定子端部绕组锥环固定结构动态特性稳健优化设计实例验证了方法的有效性和相对于确定性优化设计方法的优越性。Present optimization approaches for the mechanical structures usually neglect the uncertainty of material characteristics and the influence of their dynamic characteristics on the overall performance. Moreover, the algorithms for solving the optimization problems are often inefficient. To overcome the above shortcomings, the robust optimization method of the dynamic characteristics of mechanical structures based on double renewal Kriging models is proposed. A robust optimization model including both the means and variances of the mechanical structures＇ dynamic characteristics in the objectives is established. The model includes the deformation of mechanical structures as constraints. The kriging models that can accurately and efficiently obtain the values of objective and constraint functions are constructed based on the Latin hypercube experimental design, double update strategy, and the sample point encryption technology in both the local area of maximum error and the neighborhood of the approximate optimal solution. And then all the Pareto optimal solutions to the robust optimization problem of the mechanical structures＇ dynamic characteristics are located by integrating a neighborhood cultivation-based genetic algorithm with the double renewal Kriging model. The robust optimal design of the dynamic characteristics of the cone-shape fixed structure of a large turbogenerator＇s stator end windings verifies the validity of the proposed method as well as its superiority over the deterministic ones.

关 键 词：机械结构 动态特性 稳健优化 双层更新Kriging模型 多目标遗传算法 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]