腐蚀环境下疲劳分析的DFR方法研究

Study on DFR method under corrosive environment for fatigue analysis

将腐蚀对结构件疲劳寿命的影响当量转化为对细节疲劳额定值DFR的影响 ,建立了腐蚀条件下疲劳分析的DFR方法 .通过对标准S N曲线方程的变换 ,得到了DFR的腐蚀当量折算系数与腐蚀对疲劳寿命的影响系数之间的关系 ,并研究了其中的参数对当量折算系数的精度的影响 ,从而给出了由疲劳试验确定当量折算系数的方法 .基于地面停放预腐蚀和空中飞行腐蚀疲劳对疲劳寿命的影响相互独立的假设 ,得出了当量折算系数对预腐蚀和腐蚀疲劳的分解方法 .

Via transfer the influence of corrosive environment on fatigue life to that on detail fatigue rating equivalently, the DFR (detail fatigue rating) method under corrosive environment for fatigue analysis was established. The relation between the ratio of fatigue life under corrosive and normal environment and the corrosive convert coefficient of DFR was obtained by the standard S-N curve equation, thus the method for determining the convert coefficient was presented, in which the parameter c was shown to have little influence on its precision. Based on the assumption that the influence of pre-corrosion on ground and the influence of corrosion in flight are independent, a method for separation pre-corrosion and corrosion fatigue was proposed.