基于损伤力学预估点蚀疲劳寿命有限元法

飞机使用环境谱的不断变化会对机体结构造成腐蚀损伤,工程上难以在外场环境下进行实时损伤检测与疲劳性能试验。点蚀作为腐蚀的初始阶段,危害性大,部位也难以预测。采用损伤力学和有限元相结合的方法,以材料疲劳S-N数据为基础,将点蚀损伤认为是一种初始缺陷,建立基于损伤力学假设的点蚀损伤疲劳寿命预估方法,并提出一种改进型损伤参数反演方法。对点蚀疲劳失效过程进行数值模拟,模拟结果与试验结果吻合,证明该方法应用于金属材料点蚀疲劳问题中是合理的、可行的,为后续实际预腐蚀损伤疲劳研究奠定了基础。

Damage Mechanics Finite Element Method For Prediction Of Pitting-corrosion Fatigue Life

The continuous effects of aircraft operational environment spectrum will cause corrosion damage to aircraft structures, which is difficult to detect or test in outside field. Based on the material＇s S-N statistics and supposing the pitting-corrosion damage as the initial defect, a model to calculate the fatigue life of pitting-corro- sion damage by combining the damage mechanics with the finite element method is established, and an improved damage parameters determining method is proposed. By comparing the simulation results of pitting-corrosion damage with the test results, the method is proved to be accuracy and feasible in assessing metallic pitting-cot rosion damage and can be represented as references for further study in corrosion fatigue.