Identification of Delamination Cracks of CFRP by Electrical Potential Method

摘要

An electrical resistance method is applied for identifications of size and position of delamination cracks of components of CFRP in the present study. The method does not cause strength reduction of CFRP structures, because the method adopts reinforcement fiber itself as sensors. Due to orthotropic electrical residence of laminates of CFRP, electric potential fields of CFRP laminates are different from the fields of conventional methods for isotropic metallic materials. Authors have investigated the effect of orthotropic electrical resistance on the method by using FEM. Based on the results, identification of delamination crack size and position was impossible in the case of only an entire electric resistance change of a structure is available. In the present study, multiple points for measurement of electric potential are adopted for identifications of the delamination crack size and position. The response surface methodology is adopted to estimate delamination size and position with electric potential change data. Using FEM analysis, identification of the delamination crack size and position is conducted. As a result, a 5-segment-method is numerically shown to be very effective for identification of delamination crack size and position.