Effect of Local Off-Axis Fibers Array on Tensile Properties of CFRP Laminae
Baosheng REN, Junji NODA, Koichi GODA, Hisao KOBA
Abstract:CFRP (Carbon fiber reinforced plastics) exhibit superior mechanical properties, and are recently applied to large structural materials using the VaRTM(Vacuum assisted Resin Transfer Molding) method. In the vicinity of the resin inlet of this method, and at the joint of CFRP structures, it is pointed out that the disorder in fiber orientation often occurs. In this study, therefore, the effect of local off-axis fibers array on the tensile properties of unidirectional CFRP was basically investigated. An experimental device for making a local off-axis fibers array on a CFRP lamina was newly developed, and various unidirectional CFRP laminae were prepared by changing the fiber orientation angle and the size. The results show that the tensile strength of CFRP laminae with off-axis fibers array decreases with increasing the fiber orientation angle and the length, and depends on the degree of fiber bundle waving. On the other hand, Youngfs moduli of the CFRP lamnae show an almost constant value, which is relatively close to that of CFRP lamina without off-axis fibers array. Finally, Youngfs moduli and tensile strength of the CFRP laminae were analyzed from a proposed composite model with an off-axis fibers array, and its validity was discussed. Key Words:CFRP, Tensile properties, Laminae, Off-axis fibers, Fracture mode, Weibull statistics, Rule of mixture