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%.