Abstract
Carbon fiber (CF) reinforced polymers (CFRPs) have excellent specific strength and stiffness. In particular, CFRPs with thermoplastic resin as a matrix (CFRTPs) are widely used in fields such as aircrafts and automobiles. Recently, CFRTPs have attracted attention for its high toughness, low energy consumption during manufacturing, low material costs and recyclability. Polypropylene (PP) resin has been noted as the matrix of CFRTP due to its excellent processability and wide products range. Angle-ply CF/PP resin laminates with CF orientation angles ranging from ±15° to ±60° were investigated, and it was revealed that angle-ply CF/PP resin laminates with CF angles of ±30°, ±45°, and ±60° exhibit pseudo-ductile behavior with a significant increase in failure strain. However, the mechanism of pseudo-ductile behavior of angle-ply CF/PP resin laminates has not yet been clarified. In this study, tensile tests were conducted to investigate the effect of laminate configuration on the tensile properties of angle-ply CF/PP resin laminates with fiber orientation angles of ±45°. Finite element analysis (FEA) was also performed using a representative volume element (RVE) model of ±45° angle-ply CF/PP resin laminates to reproduce the experimental stress-strain curves, the internal stress distributions and damage growth behavior were examined, to clarify the mechanisms of pseudo-ductile behavior. The experimental results revealed that the tensile strength and failure strain varied greatly depending on the laminate configuration. The angle-ply CF/PP resin laminates with repeated +45° and -45° fiber orientation showed higher tensile strength and failure strain. The damage in the RVE model was observed at the interface between the CF bundles and the PP resin, them gradually propagated along the CF bundles, leading to the formation transverse cracks.
