腐蚀条件下疲劳寿命评定的名义应力法

提出了腐蚀条件下飞机结构疲劳寿命评定的名义应力法.以地面停放腐蚀影响系数C-T曲线为基础,通过计算反推建立飞机结构疲劳关键危险部位对应不同地面停放时间的p-S-N曲线族,应用线性累积损伤(Miner)理论估算飞机结构在使用环境谱载下的疲劳安全寿命;考虑空中腐蚀疲劳影响对疲劳安全寿命加以修正.该方法为腐蚀条件下飞机结构寿命的评定提供了有效可行的技术途径,具有重要的工程应用价值.

Nominal Stress Approach for Fatigue Life Estimation under Corrosive Environment

In order to estimate fatigue life of aircraft structures under corrosive environment, a nominal stress approach under corrosive condition (Cor NSA) was developed. Based on the curve of parking corrosion influence factor ( C ) versus parking time ( T ), p S N curves for the critical part of an aircraft component can be determined by inverse computation method, corresponding to different parking years. Thus, the fatigue safe life of aircraft structures under service environment could be predicted according to Miner's law. Furthermore, the life should be modified with flight corrosion influence considered. Finally, an example was given to show the validity of the method.