短繊維ＣＦＲＰの疲労き裂発生挙動に及ぼす切欠き穴径の影響

抄録

Fatigue crack initiation from the notch hole in the short carbon fiber reinforced plastic (sCFRP) plate is studied in this study. The sCFRP was processed by injection molding and it is constituted from surface layers in which the fiber is parallel to the molding direction and an inner layer in which the fiber is perpendicular to the molding direction. The specimen with a notch hole at the center of the plate was fatigued by loaded to the molding direction (MD specimen) and the transverse direction (TD specimen). Diameters of the notch hole is 0.5mm and 2mm. As a result, the fatigue life decreased for the notched specimen with compared to the smooth specimen and the crack generated faster in the specimen with the notch hole of 2mm than that with the notch hole of 0.5mm under the same stress amplitude. The crack propagationrate immediately after the crackinitiation was reduced in the MD specimen with a notch hole of 2mm, so it was considered that the fiber oriented to the molding direction decelerated the crack propagation at the bottom of the notch.