疲劳裂纹扩展的实时健康监测

结构中微裂纹的产生和扩展是影响结构安全及其寿命的重要因素,在裂纹产生初期就将其监测出来对于提高结构安全性来说至关重要。目前研究这一领域的学者很多,但大多都集中在孔洞等较大尺寸损伤的在线监测阶段。该文研究了真实疲劳裂纹扩展的实时在线监测方法。采用主动Lamb波监测技术及机电阻抗技术对铝试件的真实疲劳裂纹扩展情况进行了监测和分析,给出了裂纹扩展程度与信号损伤参数间的关系曲线,并对两种监测方法进行了对比,对实验结果进行了讨论。

Real-time Structural Health Monitoring for Fatigue Crack Growth

The appearance and growth of the crack in the aircraft structure is an important factor to influence the aircraft's safety and its service life.Thus it is important to detect the crack and monitoring its growth at the beginning.The real-time structural health monitoring method for fatigue crack growth is researched in this paper.The Lamb wave active diagnostic method and the electro-mechanical(E/M) impedance technique are adopted to monitoring the fatigue crack propagation on Aluminum specimens.The relationship between the signal damage index and the crack size are obtained.The two health monitoring methods are discussed and compared.