民机结构腐蚀条件下疲劳寿命评定与试验验证

Fatigue life evaluation and test verification for civil aircraft structure under corrosive environment

针对民机结构典型疲劳关键部位——机翼弦向对接部位,进行了腐蚀条件下民机结构疲劳寿命评定方法合理性的试验验证,评定了该部位腐蚀条件下疲劳寿命.通过关键部位细节模拟试件加速预腐蚀及随后的一般环境下疲劳试验,测定了预腐蚀影响系数曲线;通过腐蚀疲劳试验测定了腐蚀疲劳影响系数;通过关键部位大型结构模拟试件预腐蚀-腐蚀疲劳交替验证试验,测定了典型使用情况下的腐蚀综合修正系数,同时用腐蚀条件下民机结构疲劳寿命评定方法针对交替试验情况进行了评定,结果对比表明该评定方法是合理、可行的.并给出了机翼弦向对接部位典型使用情况下的疲劳寿命评定结论.

Rationality of the fatigue life evaluated method for civil aircraft structures under corrosive environment was validated by test for the chordwise joint parts of wings which were typical fatigue critical parts of civil aircraft structures. And the fatigue life of this part under corrosion was evaluated. The pre-corrosion curve was obtained by pre-corrosion and followed fatigue test in common environment on simulated specimens of this critical part. The corrosion-fatigue influence factor was obtained by corrosion-fatigue test on the same specimens. Pre-corrosion and corrosion-fatigue alternation tests were carried out on large-scale simulated specimens. And the synthetical correction factor of corrosion under typical using condition was obtained. The correction factor of the alternative test was also obtained by evaluated method. The comparison between the two results shows that the evaluated method is rational and validity. And the fatigue life evaluated result of the chordwise joint parts of wings under corrosion was given.