Author(s)

Akira Todoroki¹, Keisuke Ohara², Yoshihiro Mizutani¹, Yoshiro Suzuki¹, Ryosuke Matsuzaki³

¹Department of Mechanical Sciences of Engineering, Tokyo Institute of Technology, Tokyo, Japan.
²Tokyo Institute of Technology, Tokyo, Japan.
³Department of Mechanical Engineering, Tokyo University of Science, Chiba, Japan.

Carbon fiber reinforced polymer composites (CFRP) have been applied to aerospace and automobile structures. For many CFRP structures, mechanical metallic fasteners are usually adopted. For the fasteners used in internal structures such as a wing box, the damage to the CFRP structures around fastener holes is visually quite difficult to find. A simple method to find the damage around fastener holes is required. In this study a self-sensing time domain reflectometry (TDR) method is newly applied to detect bearing failure around the fastener holes of CFRP structures. A microstrip-line method is generally used to create a transmission line. When the transmission line is mounted near the metallic fasteners, they may affect the impedance of the transmission line. In this study, the effect of distance between the fasteners and the transmission line was numerically investigated using a finite difference time domain analysis method. After finding the appropriate distance, experiments were performed to detect the bearing failure around a fastener hole. The experiments showed the performance of the self-sensing TDR for detecting bearing failure.

Composites, Time Domain Reflectometry, Self-Sensing, Bearing Failure, Fasteners, Monitoring

Todoroki, A. , Ohara, K. , Mizutani, Y. , Suzuki, Y. and Matsuzaki, R. (2015) Self-Sensing TDR for Bearing Failure Detection of CFRP Laminate Fastener Hole with Particular Reference to the Effect of Fasteners. Open Journal of Composite Materials, 5, 60-69. doi: 10.4236/ojcm.2015.53009.