Carbon Fiber Prepreg Composites Failure Mechanism Based on Electrical Resistance Method during Hight-Strain Rate Loading

Abstract

In this study, a unidirectional and plain weave carbon fiber/epoxy prepreg was used as the raw material, and the prepreg tape winding process was used to prepare carbon fiber/epoxy prepreg composites with 65% and 75% carbon fiber volume content, respectively. Based on traditional damage experiments and mechanical measurements, electrical measurements are introduced to study the damage to carbon fiber prepreg composites. The damage behavior of the carbon fiber prepreg composite under a high-speed impact load was monitored using the resistance method. By arranging electrodes on the sample and tracking the change in resistance during the entire process of high-speed impact of the material, the relationship between the damage and the change in resistance parameters of the carbon fiber prepreg composite winding products under high-speed impact was determined. The stress-strain curve and the final failure mode of the sample and the microstructure mechanics of carbon fiber prepreg winding products under different strain rates were analyzed. These results indicate that, as the change in resistance over time was almost stable from 0 to 200 μs. From 200 to 250 μs, the resistance decreases sharply; from 250 to 400 μs, the resistance approximates a plateau. From 400 to 500 μs, the resistance value increases again; at this time, the resistance value decreases to 3.2% of the initial resistance value.