Numerical and experimental investigation on the mechanical performance of large-tow carbon fiber reinforced polymers laminate

The mechanical properties of large-tow carbon fibers (LCFs) reinforced polymers are crucial for determining practical value and future prospects. This article investigates the mechanical properties and influencing factors of LCF by conducting longitudinal tensile and flexural tests on laminates made from LCFs. The experimental results revealed that the tensile performance of the laminates was 46% lower than the predictions from finite element analysis (FEA). The maximum destructive stress loss is nearly doubled. Even worse, the flexural performance has been compromised by about 3.8 times. To understand the reasons behind this discrepancy, scanning electron microscopy (SEM) revealed significant progressive damage on the fracture surfaces of the laminates. This damage resulted from the infiltration of resin and fibers during the manufacturing process. Additionally, the experimental load-displacement curve indicates that this localized damage occurs prior to the overall fracture failure, which greatly diminishes the overall performance of the laminates. The research findings suggest that, despite using relatively precise LCF laminate manufacturing methods, the inherent properties of the fibers limit the enhancement of their mechanical properties. This study offers valuable insights for improving the manufacturing processes of LCFs laminates and for enhancing the mechanical performance.