射出成形した短繊維CFRPの疲労き裂の発生に及ぼす繊維配向の影響

抄録

The short-fiber reinforced plastic made by injection molding have three-layer structure where two skin layers sandwich the core layer. The fiber direction on the skin layer of injection-molded plates is nearly along the molding flow direction (MFD), and that of the core layer is perpendicular. Three types of specimens loaded to parallel (MD), 45°(45°) and perpendicular (TD) to molding direction were fatigued. As a result, fatigue strength decreased in the order of MD, 45°, TD and the stiffness of the specimens decreased with stress cycles. Crack initiation and propagation life were estimated and the cause of the decrease in the stiffness was discussed.