The effect of electrical anisotropy on delamination detection sensitivity of self-conductive carbon fiber composite

The electrical resistance change with respect to delamination in self-conductive carbon fiber/epoxy (CF/EP) composite was investigated. As an example of application, the case of a Double Cantilever Beam (DCB) experiment was considered, with the aim to demonstrate the damage sensing capacity of the electrical resistance change method. Two-dimensional finite models were performed to figure out the potential distribution of a delaminated composite with different electrical anisotropy ratios. Based on the simulation results and the particularity of the CF/EP composite, a theoretical model was proposed to predict the electrical resistance change of the laminate with delamination increment, and the anisotropy effect was investigated using the model. To verify the simulation and modeling result, both CF/EP composite and conductive fillers modified CF/EP composite were prepared to examine their delamination detection sensitivity though DCB experiment, the experimental result shows the damage detection sensitivity of modified specimen shows a little increase compared with unmodified specimen, furthermore, theoretical prediction shows a satisfactory agreement with the experimental data.