Monitoring fatigue damage of an adhesive joint using fiber optics sensors

6th International Conference on Fracture Fatigue and Wear

Shin, C.S.^1 ; Yang, Y.J.^1 ; Liaw, S.K.^2

Mechanical Engineering, National Taiwan University, No.1, Roosevelt Road, Taipei

10617, Taiwan^1

Elelctronic and Computer Engineering, National Taiwan Univ of Science and Technology, No.43, Keelung Rd., Taipei

106, Taiwan^2

关键词: Fiber optics sensors;    Joining techniques;    Monotonic and cyclic loading;    Non-destructive evaluation techniques;    Online monitoring;    Optical fibers with Bragg gratings;    Single lap joints;    Structural failure;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/843/1/012032/pdf
DOI  :  10.1088/1742-6596/843/1/012032

来源: IOP

【 摘 要 】

Adhesive joining has many merits over traditional joining techniques. However, adhesive joints are susceptible to damage and degradation caused by service loading. If such degradation went undetected, serious structural failures and catastrophic outcome might follow. It is difficult and economically unviable to carry out regular examination on the joint integrity using conventional non-destructive evaluation techniques, especially in the case of practical structures with large scale adhesive joining. In this work, optical fibers with Bragg grating (FBG) sensors embedded in single lap joints has been demonstrated to be able to detect internal damage caused by monotonic and cyclic loading. FBG sensor works by reflecting specific wavelengths from a broad spectrum incident light. The wavelengths reflected depend on the strain on the FBG. Internal damages will perturb the strain field in the joint and thus change the shape of the reflected FBG spectrum. With embedded FBG sensors, it is possible to achieve on-line monitoring of the joint integrity in an economical way.