Reliability Evaluation of Novel Core-in-Sheath-Type Carbon/Glass Hybrid Thermoplastic Composite Rods

In the Center of Innovation science and technology based radical innovation and entrepreneurship (COI STREAM) program, “construction of next-generation infrastructure using innovative materials ~realization of safe and secure society that can coexist with the earth for centuries~”, we focus on the reliability evaluation of the novel core-in-sheath-type carbon/glass hybrid thermoplastic composite rods (hybrid rods). It is necessary to characterize the mechanical properties of FRP because the cables in the infrastructures are usually used in a rope configuration. We also investigated the tensile properties of the hybrid ropes consisting of seven hexagonally close-packed twisted rods with two layers under static and fatigue loadings. The static and fatigue properties of the hybrid ropes can be estimated using a single hybrid rod. Therefore, we showed the various evaluation results for the single hybrid rods in this paper. The morphologies (including constituent volume fractions) of the hybrid rods were characterized by optical and gravimetric methods, and the tensile, axial and transverse compressive, and flexural tests of the hybrid rods under static and fatigue loadings were performed. In addition, interfacial mechanical properties between the carbon fiber bundle core and glass fiber bundles were investigated. Moreover, data accumulation and statistical analyses have been conducted to evaluate the effects of environmental factors, such as temperature, water, and ultraviolet irradiation, on their static properties.