为解决腐蚀疲劳条件下无法由断口判读获得(a，N )数据集以确定裂纹扩展公式参数的问题，提出了确定疲劳裂纹扩展参数的寿命反推方法。通过与用(a，N )数据集全部数据拟合结果的比较， 证明该方法在指数b= 1的情况下适用, 而在b≠1 时偏差较大；指定破坏概率的载荷循环数和裂纹长度的比较结果, 说明该方法的结果可用于概率损伤容限分析。

采用2024-T3铝合金含中心孔试件进行了实验室空气环境和潮湿空气环境下的疲劳寿命实验及升降法实验，研究了潮湿空气环境对2024-T3铝合金疲劳性能的影响．结果表明，潮湿空气环境显著降低了2024-T3铝合金的疲劳性能，潮湿空气环境对其疲劳寿命特征值和疲劳强度均值的影响系数分别为O.6059和0.8722；在潮湿空气环境中疲劳寿命的分散性变大，用疲劳寿命的中值或特征值得到的腐蚀影响系数进行可靠度95％的腐蚀环境下的寿命修正，将得到偏危险的结果．用潮湿空气环境对基本可靠性寿命的影响系数由标准g-Ⅳ曲线折算得到的对疲劳强度的影响系数与升降法测得的对疲劳强度的影响系数基本一致，在潮湿空气环境下标准g-Ⅳ曲线参数仍然适用．

Crack propagation tests were conducted with CCT specimens made by 2024-T3 Aluminum alloy in benign and corrosive environments to investigate the stochastic characteristics of crack growth. A random variable probability crack growth model, base on the modified form of Paris law, was used to characterize the stochastic performance. Distribution significance test has been done, which shows that the random variable X can be considered reasonably to follow log-normal distribution in all the 4 kind of environments. Variance analysis indicates that the scatter in wet air is greater than that in laboratory air significantly. Expressions for the probability distribution of crack size at any given loading cycle and the probability distribution of the random fatigue life at which a given crack size is reached were discussed. The corresponding calculations for the crack length distribution and P-a-N curves with certain reliability were carried out. The comparisons with experimental data indicate the validity of the proposed method.

The influence of environmental corrosion on fatigue life of 2024-T3 aluminum alloy is investigated in this paper. Experiments with center-hole specimens and CC (T) specimens are conducted and reported. The test result shows that the corrosion influence is becoming serious while the environmental causticity is increasing, and the influence on crack initiation life is greater than that on crack propagation life. Analysis of the test data also indicates that the environmental causticity enlarges the dispersivity of fatigue life. Using the corrosion-modification-factor obtained by eigenvalue or mean value to prediction the fatigue life with high reliability will cause an unconservative conclusion.

为使腐蚀环境下民机结构疲劳分析的细节疲劳额定值(DFR)方法具有更广泛适用性，对DFR 腐蚀影响系数与腐蚀环境的关系进行了研究，将DFR的腐蚀影响系数分解为地面停放腐蚀影响系数和空中腐蚀疲劳影响系数，建立了地面停放腐蚀影响系数与地面停放腐蚀时间的关系，以及空中复杂综合环境腐蚀疲劳影响系数与单一介质环境腐蚀影响系数的关系。通过试验测定了各种典型情况的DFR腐蚀影响系数，试验结果说明DFR腐蚀影响系数随着地面停放腐蚀时间的增加和环境腐蚀性的增强而降低，腐蚀疲劳的影响较停放腐蚀的影响更严重。分析实例具体说明了腐蚀条件下DFR方法的具体步骤和所需数据，并体现出疲劳分析中计及腐蚀影响的必要性。