航空装备关键件微动疲劳寿命预测

Fretting Fatigue Life Prediction of Main Components in Aviation Equipment

摘要:

通过微动疲劳损伤机理分析,以微动疲劳接触应力计算入手,建立了航空装备关键件中一种较为普遍的圆柱/平面接触微动疲劳结构的有限元全局模型和子模型,通过边界条件误差和离散误差分析,提高了计算精度和计算效率。以断裂力学为基础,根据复合型裂纹断裂判据,用改进的裂纹闭合积分法计算了裂纹尖端应力强度因子,引入应力强度因子影响系数,建立了微动疲劳裂纹扩展寿命预测模型,确定了模型中的参数,通过预测寿命与试验值的对比验证了该模型的正确、有效性。

Abstract:

Based on the contact stress computing and analysis of fretting fatigue damage mechanism, the global model and sub-model of fretting fatigue structure with cylinder and plane contact consisted in main components in aviation equipment was established. The the computing precision and efficiency were advanced with analysis of boundary condition error and discretization error. According to the part mechanics and part criterion of composite crack, a new model for predicting propagation life of fretting fatigue crack of was presented based on stress intensity factor (SIF) computing in crack tip. Parameters were confirmed, and then the rationality and effectiveness of the model were validated according to the contrast of experiment life and predicted life.