基于场强法的燃烧室机匣后衬套安装座疲劳寿命预测

由于局部应力应变法存在缺陷而引入场强法,对缺口构件的疲劳寿命预测问题进行研究。给出了应力场强法估算缺口构件疲劳寿命的基本框架和分析计算步骤,通过算例对场强法重要参数场径的影响因素、应力集中系数和权函数进行了探讨,并对场强计算中的有限元网格细化问题进行了初步探讨。采用场强法和局部应力应变法对某型发动机燃烧室机匣后衬套安装座进行了疲劳寿命预测。结果表明：利用场强法预测出的寿命更接近试验结果。

Fatigue Life Assessment of Combustor Casing Rear Bush Installation Seat Based on Field Intensity Approach

The procedure of fatigue life assessment of notch component on ＂stress field intensity＂（SFI） approach was studied due to the defect of local stress strain method.The basic framework and the calculaiton procedure of the fatigue life assessment of notch component by stress field intensity approach were presented.The factors on field radius,stress concentration factor,weigh function for the calculation of field intensity were studied by examples.The prilimanery investigation on FE grid finning were completed for the calculation of field intensity.The assessment value of fatigue life of the combustor casing rear bush installation seat were conducted by SFI method and local stress-strain method.The results show that the assessment value of the fatigue life using SFI method is closer to the test result.