Effect of Dent on Self-Sensing Method of CFRP

Abstract

Authors’ group has been done researches on the damage monitoring of the laminated Carbon Fiber Reinforced Plastic (CFRP) using the electrical resistance change method. The method adopts reinforcement carbon fibers as sensors, and it is called self-sensing method. Using thin CFRP laminates, delamination crack location and dimension are identified with the electrical resistance change method. However, the electrical resistance decreases when a delamination crack is made in a thick CFRP beam. The present paper experimentally investigates the effect of the dent for the measurements of electrical resistance change. Indentation tests are performed for the thick CFRP plates. The effect of the dent is calculated compared with the effect of piezoresistivity caused by the residual stress relief. As a result, the effect of the dent is larger than the effect of the residual stress relief for the thick CFRP. For the thick CFRP, dents cause the significant reduction of the electrical resistance in the thickness direction, and that causes electrical resistance decrease.

Review on the Electrical Resistance/Conductivity of Carbon Fiber Reinforced Polymer

“…They adopted reinforcement carbon fibers as sensors to identify the delamination crack in thin CFRP laminates. The change of electrical resistance is a main parameter to indicate the location and dimension of the delamination [67]. The authors also used the time difference between the measured signals reflected from a transmission line end and from damage respectively to determine the location of the damage [68].…”