Time Domain Reflectometry for Damage Detection of Laminated CFRP plate

摘要

Recently, high toughness Carbon Fiber Reinforced Polymer (CFRP) laminates are used to primary structures. The tough CFRP yields small fiber breakages when delamination crack is made in many cases. This requires a detection system of fiber breakages at low cost for large laminated CFRP structures. In the previous study, Time Domain Reflectometry (TDR) method is adopted for the detection of the fiber breakages of the CFRP plate. In the present study, damage detection in the transverse direction is performed using the array of electrodes. The method is applied to a CFRP strip specimen of 2 m length with a notch. As a result, all electrodes detected the small notch. This means the electrode array did not detect the location of the damage in the transverse direction. Computer simulation was performed to confirm the pulse wave propagation in the transverse direction using Finite Difference Time Domain (FDTD) method. The FDTD successfully showed the pulse signal propagation in the transverse direction. Future work is indispensable to develop a new technology to detect the location of the damage in the transverse direction.