基于RSM与NSGA-Ⅱ的燃气灶外壳零件成形质量多目标优化

Multi-Objective Optimization of Forming Quality of Gas Stove Shell Parts Based on RSM and NSGA-Ⅱ

为提高燃气灶外壳零件的成型质量和安全性能,课题组基于DYNAFORM建立燃气灶外壳的有限元模型并完成优化模拟。以圆角半径A、压边力B和模具间隙C作为影响零件成形质量因素,以最大减薄率y1和最大增厚率y2作为优化目标,应用Box-Benhnken(BBD)设计响应面(RSM)试验;采用DYNAFORM 6.0有限元软件模拟试验并获得样本数据,得到y1与y2的多项式回归响应模型;结合遗传算法对多目标优化函数进行优化求解,根据带精英策略的改进型非支配排序遗传算法(NSGA-Ⅱ)获得优化后Pareto最优解集。最后选取了最优工艺参数组合:取整得到A为13 mm,B为335kN,C为0.84 mm。根据NSGA-Ⅱ预测结果y_(1)为23.32%,y_(2)为2.80%,经数值模拟验证,最大减薄率和最大增厚率分别为23.39%和2.96%,因此试验结果和预测结果误差低至0.3%。文中采用的零件成形质量多目标优化方法准确度高,为提高同类外壳零件的成形质量提供一种有效的优化方案。

In order to improve the forming quality and safety performance of gas stove shell parts,a finite element model of the gas stove shell was established based on DYNAFORM and the optimization simulation was completed.Fillet radius A,blank holder force B and mold gap C were taken as the factors affecting the forming quality of the parts,and the maximum thinning rate y1 and maximum thickening rate y2 were taken as optimization targets.The box benhnken(BBD)was used to design the response surface(RSM)test.The polynomial regression response model of y1 and y2 was obtained by using DYNAFORM 6.0 finite element software to carry out the simulation test and obtain the sample data.Combined with genetic algorithm,the multi-objective optimization function was optimized and solved.The optimized Pareto optimal solution set was obtained according to the improved non-dominated sorting genetic algorithm with elite strategy(NSGA-Ⅱ).The optimal combination of process parameters was selected which took an integer to get A as 13 mm,B as 335 kN,and C as 0.84 mm.According to the prediction results of NSGA-Ⅱ,y_(1) is 23.32%and y_(2) is 2.8%.Numerical simulations show that the maximum thinning rate and maximum thickening rate are 23.39%and 2.96%respectively,and the error between the test results and the prediction results is as low as 0.3%.The proposed multiobjective optimization method of part forming quality has high accuracy and provides an effective optimization plan for improving the forming quality of similar shell parts.