涡轮叶片疲劳-蠕变寿命稳健性优化方法

为了清晰地反映涡轮叶片的疲劳-蠕变交互作用,提高寿命预测结果的准确性及可靠性,并改善涡轮叶片疲劳寿命对随机变量的敏感程度,分别采用Manson-Coffin公式和Larson-Miller方程计算了涡轮叶片的低循环疲劳寿命和蠕变持久寿命,利用修正的时间-寿命分数法计算了涡轮叶片疲劳-蠕变损伤,在此基础上,将响应面法(RSM)与果蝇优化算法(FFOA)相结合,考虑载荷、材料参数、疲劳-蠕变交互程度的不确定性,对涡轮叶片疲劳寿命进行了稳健性优化设计。优化结果表明:涡轮叶片疲劳-蠕变小时寿命的概率区间减小了8.48%,验证了该优化方法的工程可行性。

Robust Optimization Method for Turbine Blade under Fatigue-Creep Interaction

In order to reflect fatigue-creep interaction of turbine blade clearly, raise the accuracy and reliability of life prediction result and improve sensitivity of fatigue life to random variables at the same time. low cycle fatigue life and creep life of turbine blade were calculated by Manson-Coffin formula and Larson-Miller equation, fatigue-creep damage was obtained by modified time-life fraction method. Robust optimization design of turbine blade fatigue life was developed by combining RSM (Response Surface Methodology)and FFOA (Fruit Fly Optimization Algorithm), considering the uncertainty of loads, material parameters and the degree of fatigue-creep interaction. The results show that probability interval of fatigue-creep life for turbine is decreased by 8.48%, which verify the feasibility of this optimization method.