基于响应面法的可靠性稳健设计优化

针对极限状态函数和结构性能函数为隐式的结构可靠性稳健设计优化问题,将结构性能稳健性、可靠性灵敏度稳健性与6σ稳健设计思想相结合,建立了一种基于响应面法的可靠性稳健设计优化模型并给出了具体算法.采用多项式拟合结构性能函数和极限状态函数,推导了基于响应面函数的1阶可靠度指标以及性能函数均值和均方差的计算方程；将结构可靠度作为基本约束条件,采用序列二次规划法得到稳健设计优化结果.运用该方法对某涡轮叶片型线进行设计优化,经过优化后,静、动叶的动能效率均值分别提高1.5％和6.4％,动叶片最大应力均值下降7.9％,动叶叶身最大变形均值下降5.6％,动叶片结构强度可靠度由初始的91.3％提高到了99.9％.

Reliability robust design optimization based on response surface method

To solve the problem of reliability robust design optimization of structure with implicit limit state functions and limit output performance functions,the robustness of the performance,reliability sensitivity robust and six sigma robust design were integrated,and a reliability robust design optimization model based on response surface method was presented involving the detailed calculation processes of the method.The second-degree polynomials were introduced to simulate the output performance functions and the limit state functions of the structure.The equations of the first order reliability index,the mean value and the standard deviation of the structure were calculated based on the response function.Then taking the structural reliability as the basic constraint condition,the final optimization result with the sequential quadratic programming method was obtained.Finally the example was introduced to explain and validate the model.The method was used to design the model lines of a gas turbine blade.After design optimization,the results indicate that the aerodynamic efficiencies of the guide blade and working blade increase by 1.5% and 6.4% respectively,and the maximum stress and the maximum strain of the working blade decrease by 7.9% and 5.6% respectively.The intensity structural reliability of the working blade increases from 91.3% to 99.9%.