腐蚀环境下多裂纹结构的概率损伤容限分析

一般环境下疲劳多裂纹结构的概率损伤容限分析方法已经比较成熟.为满足恶劣环境下工作的老龄飞机结构疲劳可靠性评定的需要,尝试建立腐蚀环境下疲劳多裂纹结构的概率损伤容限分析方法.通过综合考虑空中飞行腐蚀和裂纹扩展随机性的影响,采用对数正态随机变量模型描述裂纹扩展过程,得到可靠度-寿命曲线.通过实例,验证了方法的可行性.

Probability Damage Tolerance Analysis for Structures with Multiple Fatigue Cracks under Corrosive Environment

Analyzing damage tolerance capability of structures with multiple fatigue cracks is an important task for the current assessing of structural fatigue reliability of aging airplanes. Based on probability damage tolerance theory for structures with multiple fatigue cracks under normal environment, a probability damage tolerance analysis method was established for structures with multiple fatigue cracks under corrosive environment. Using the model of logarithmic normal random variables to describe crack propagation processes, a reliability life curve is presented for the structures with multiple cracks under corrosive environment, by considering the influences of the air during corrosion flight and the randomicity of crack propagation. A numerical example is given to prove the validity of the proposed method.