Accurate Tensile Strength Distribution of PAN-based Carbon Fibers

Abstract

The tensile strength distribution of carbon fibers at short gauge lengths is vital for understanding the tensile strengths of carbon-fiber-reinforced plastics (CFRPs). However, determining the tensile strength distribution at short gauge lengths is challenging, and only a few studies have attempted to do so. This study presents the key factors required to determine the accurate tensile strength distribution, such as, measurement of cross-sectional areas of single fibers, clamp effect in single fiber tensile (SFT) test, residual strain in single fiber composite (SFC) test, and the consistencies of the SFT and SFC tests. With these considerations, the bimodal Weibull distribution model was employed to describe the experimental results. The tensile strength distributions of polyacrylonitrile (PAN)-based carbon fibers at short gauge lengths were narrower than those at long gauge lengths. This study provides significant implications to understand the accurate tensile strength distribution of PAN-based carbon fibers and the tensile strength of resin-impregnated fiber bundles. Furthermore, this study may provide design criteria for the material development of CFRP composites and for enhancing their tensile strengths.