基于缺口疲劳方法的结构疲劳寿命评估探索

Exploration of Structure Fatigue Life Based on Notch Fatigue Life Method

目前对复杂结构在振动环境下的疲劳寿命仿真预测研究进展较快,但对带制造、加工缺陷结构的振动疲劳寿命评估相对较少。文中基于缺口疲劳寿命方法,以一种含有工艺铸造气孔缺陷的天线座单元为例,建立仿真模型并进行了模态修正,从而降低模型准确度对疲劳寿命预测的影响,通过引入缺口疲劳系数来修正含有工艺缺陷的材料S-N曲线,寿命分析结果与试验结果吻合度较好,可供同类结构疲劳寿命评估参考。

Researches on the fatigue life simulation and prediction of complex structures in vibration environment develop rapidly, but there are few assessments on the vibration fatigue life of structures with manufacturing and processing defects. In this paper, based on notch fatigue life method using the antenna pedestal unit containing the casting porosity defects as an example ,the simulation model is established and the mode is wpdated. This can reduce the impact of model accuracy on the fatigue life predication. By introducing the notch fatigue life coefficient, S-N curve of the material is revised and the life analysis result matches the test re- sult perfectly,which may provide references for the assessment of fatigue life of similar structures.