摘要
腐蚀环境下飞机金属结构疲劳关键件的寿命评定是飞机结构寿命监控的重要工作。为此,模拟飞机结构经历的"地面腐蚀+空中疲劳"过程,构建了考虑静强度要求的腐蚀/疲劳交替寿命预测模型。首先分析了结构静强度要求对腐蚀损伤的限制,然后基于腐蚀影响系数法提出了将腐蚀损伤当量成疲劳寿命的衰减;进一步分析了结构静强度对疲劳累积损伤的影响;最后,建立了基于静强度和累积损伤准则的腐蚀/疲劳交替寿命预测模型。计算结果表明:由于结构静强度的要求,不同使用强度下飞机结构疲劳寿命和日历寿命的消耗基本服从分段的线性关系;在使用强度为4.517万次/天和3.591万次/天时,疲劳寿命和日历寿命的消耗存在"平衡点",可以通过调整使用强度,达到二者同时到寿的目标。该模型可以为飞行计划的调整提供参考。
Life evaluation for aircraft metal fatigue critical components under corrosive environment is an important job to surveil aircraft structural safety.Therefore,the process of 'corrosion on the ground plus fatigue in the air' is simulated to establish a corrosion and fatigue alternative predicted model to satisfy the static-stress demands.Firstly,the requirement of structural static-stress rule to corrosion damage is analyzed.Then,a method to convert corrosion damage into equivalent fatigue cycles is proposed based on the corrosion-affected coefficient method.Furthermore,the requirement of structural static-stress rule to cumulative fatigue damage is also analyzed.Finally,the corrosion-fatigue alternative life predicting model based on the rules of static-stress and cumulative damage is established.The relationship of fatigue and calendar life under different operating strength basically submits to sectional linear function,and there are 'balance points' between fatigue and calendar life at the strength of 45170 cycles/day and 35910 cycles/day according to static-stress rule.The result obtained reveals that the model may provide reference for the adjustment of flight planning.
出处
《应用力学学报》
CAS
CSCD
北大核心
2012年第5期589-594,632,共6页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金(50975284)
陕西省自然科学基金(SJ08E107)
关键词
腐蚀/疲劳
日历寿命
疲劳寿命
静强度准则
使用强度
corrosion/fatigue,calendar life,fatigue life,static-stress rule,operating strength
