摘要
飞机金属结构疲劳损伤的实时在线监测,对于保证飞行安全是极其重要的。在文献[13]的基础之上,提出一种花萼状涡流传感器,并搭建基于该传感器的疲劳裂纹监测系统,进行程序载荷谱下的2A12-T4铝合金拉伸疲劳试验件的疲劳损伤在线监测试验,通过对比传感器监测结果和疲劳裂纹断口定量分析结果,对传感器的疲劳裂纹定量监测能力进行验证。监测试验结果与试件断口定量分析对比结果表明,在试件疲劳裂纹扩展过程中,传感器的各感应线圈通道的幅值比信号的变化较为明显,同时具有阶跃特征,当裂纹从一个感应线圈通道位置扩展至其相邻通道位置时,该感应线圈通道的幅值比信号会急剧增加,而当裂纹穿出其相邻通道位置时,该感应线圈通道的幅值比信号增加速度显著减缓;根据阶跃特性,将各感应线圈通道的幅值比信号开始快速增加的'拐点'作为裂纹前缘进入相应感应线圈通道的特征,花萼状涡流传感器可以实现疲劳裂纹的定量监测,监测精度为1 mm;离疲劳源较近的感应线圈通道的幅值比信号可定性监测结构的疲劳累积损伤程度。
Fatigue damage monitoring of aircraft metallic structure is critical to flight safety. Based on the previous work ofref.[13], a kind of rosette eddy current sensor is proposed, and monitoring experiment of 2A12-T4 aluminum alloy under constant load based on constructed fatigue-crack monitoring system is carried out, which intends to validate the quantitative crack-monitoring capability of rosette eddy sensor through comparison between experimental result and fractographic quantitative analysis result. The comparison result shows that amplitude ratio of sensing-channel signal is sensitive to the crack propagation, and has step feature. When the crack extends from the position of sensing-channel to adjacent channel position, the amplitude ratio of sensing-channel signal increases sharply, and then increases slowly after the adjacent channel position. Viewing the changing-point as indication of crack position, the quantitative-monitoring capability of fatigue crack is achieved by rosette eddy current sensor with precision of 1 mm, and the sensing-channels near fatigue source ate capable of qualitative-monitoring of accumulated fatigue damage.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第2期1-7,共7页
Journal of Mechanical Engineering
基金
国家高技术研究发展计划资助项目(863计划
2009AA04Z406)
关键词
结构健康监测
花萼状涡流传感器
断口定量分析
飞机金属结构
疲劳损伤
Structural health monitoring Rosette eddy current sensor Fractographic quantitative analysisAircraft metallic structure Fatigue damage
