818 キンク損傷がPBO繊維の引張破壊挙動に及ぼす影響(GS4-4 材料力学・計算力学)

Abstract

In this paper, effect of kinking damage on tensile fracture behavior of poly-p-phenylene benzobisoxazole (PBO) fiber was investigated in monofilament tests. Kinking damages was created on surface of virgin fiber by winding bundle fibers to steel rod. Diameter of steel rod was set to 5, 2.5, 1.25 and 0.65 mm. Kinking damage density was defined to evaluate occurrence of kinking damage owing to bundle fiber was wound onto the steel rod. The fracture surface was observed using Scanning Electron Microscope (SEM). It was found that the tensile strength of fiber with kinking damage was well fitted the Weibull distribution function with 2 parameters. The tensile strength of PBO fiber with kinking damage was explained in the concept of the effective volume. It was shown that the crack growth of PBO fiber with kinking damage developed along the kinking damage.