Electrical and Mechanical Characterization of Hybrid CFRP Sheets

Abstract
This study brings forth the electrical and mechanical models of a new kind of hybrid carbon fiber-reinforced polymer (HCFRP) composites consisting of several types of carbon fibers with different strengths and Young’s moduli. Then, an experimental program with some main variables including the carbon fiber types and their volume fractions has been carried out. Six types of specimens have been fabricated to investigate the mechanical properties and self-health monitoring function of the HCFRP sheets with different types of carbon fiber and volume fractions. The experimental results indicate that the hybridization of several types of carbon fibers is an effective method for upgrading the mechanical properties of the HCFRP sheets. The electrical resistance of the HCFRP sheets changes with the strain in a stepwise manner due to the gradual macro-fracture of different types of carbon fibers. The number of steps is related to the number of carbon fiber types. It has also been shown that the ruptured carbon fibers can still contribute to the current conduction through transverse electrical conduction. The good correlations between the mechanical and electrical behaviors reveal the self-health monitoring function of the HCFRP sheets.