2003 年 29 巻 4 号 p. 136-142
This paper describes a creep rupture model considering the interfacial debonding in broken fibers in unidirectional polymer matrix composites reinforced by glass fibers. Interfacial debonding was accompanied with fiber breaks under the tensile load, depended on the fiber stress at the simultaneous fiber breaks. The interfacial debonding length, fiber strength and an interfacial shear stress were investigated by the fragmentation test. A vinylester/glass fiber interface's properties were investigated by the fragmentation test. Subsequently, the debonding length and a stress recovery length were quantitatively studied and it was found out that the relation between the strength and the length of fiber was linear. The debonding length was calculated by a measure of the distance between the fiber breaking faces. The interfacial debonding length was taken into the Curtin's fracture model. Moreover, the creep test of the unidirectional composites, it was vinylester resin matrix reinforced by glass fibers, was performed to investigate the creep constants. Then, the prediction in the use above parameters of the creep rupture time was discussed.