Tensile properties of novel carbon/glass hybrid thermoplastic composite rods under static and fatigue loading

Abstract

Novel carbon/glass hybrid thermoplastic composite rods have been developed consisting of a PAN-based carbon fiber, an E-glass fiber, and a thermoplastic matrix. Three types of hybrid rods with different carbon/glass ratios were then fabricated. The surface and cross-sectional morphologies of the hybrid rods were observed using a digital microscope. Additionally, the volume fractions of carbon/glass fibers, matrix, and void were determined by specific gravity measurements and thermogravimetric analyzes. The glass fibers in the hybrid rods display a braided structure of the 2/2 twill weave. The braid angle (defined as the orientation angle of the interlacing yarns with respect to the longitudinal axis of the rod) ranged from 22.3° to 35.2°. The various volume fractions were in the ranges of 24.6-46.2% for the carbon fiber, 23.2-39.8% for the glass fiber, 23.4-25.5% for the matrix, and 7.3-10.2% for the voids. The tensile properties and fracture behavior of the hybrid rods under static and fatigue loading were also investigated. For the static tests, the stress applied to the specimen was nearly linearly proportional to the strain until the failure of all-hybrid rods. The tensile modulus, strength, and failure strain of the hybrid rods were measured in the ranges of 65-91GPa, 1.42-1.84 GPa, and 2.1-2.2%, respectively. The tensile modulus and strength increased as the volume fraction of the carbon fiber increased. However, the failure strain decreased as the volume fraction of the carbon fiber increased. For fatigue tests, the maximum applied stress-number of cycles to failure (S-N) curves for all-hybrid rods were obtained from 0.1 of the stress ratio (minimum/maximum stress) and 10 Hz of the loading frequency. The fatigue strength at 10 7 cycles for all-hybrid rods was less than 30% of ultimate breaking stress. The fatigue performance of the hybrid rods was significantly lower than that of conventional carbon fiber reinforced polymer matrix composites and steel rods. The voids in the hybrid rods affected the fatigue tensile properties.

Transverse Compressive Properties of Carbon/Glass Hybrid Thermoplastic Composite Rods

“…The novel carbon/glass hybrid thermoplastic composite rods consisting of unidirectional polyacrylonitrile-based carbon fiber bundle (T700SC-24000-50C, Toray Industries, Inc.), braids of E-class glass fiber bundle (ECG751/01ZY-95T, Nippon Electric Glass Co., Ltd.), and thermoplastic epoxy matrix were developed by the Komatsu Seiren Co., Ltd. Three types of hybrid rods having different carbon/glass ratios were fabricated and described as 24K1P (one carbon fiber bundle of 24,000 filaments), 24K2P (two carbon fiber bundles of 48,000 filaments), and 24K3P (three carbon fiber bundles of 72,000 filaments). Detail information about the hybrid rods can be found in the literatures [11,12] and are shown in the Supporting Information.…”

“…, and Weibull modulus (m L ) in each type of hybrid rod are also shown in Supporting Information [11,12]. The F-U curves showed large nonlinear behavior and complicated shape.…”

“…Recently, Naito et al characterized the morphology and tensile properties of the hybrid rods (24K1P, 24K2P, and 24K3P) under static and fatigue loading [11,12]. The braiding angles, volume fractions of elements (carbon fiber, glass fiber, matrix, and void), tensile properties of each hybrid rod under static and fatigue loading are found.…”

“…The diameter (d) of the hybrid rod was measured in previous studies using a micrometer [11,12]. The average diameters of the hybrid rods are summarized in Supporting Information [11,12]. The volume fraction of carbon fiber (…”

“…Fig. 4 shows the relationship between the transverse compressive strength and the volume fraction of carbon fiber, V CF , obtained from the previous investigation [11,12], and were shown in Supporting Information. The tensile strength increased by increasing V CF , while the σ TCi decreased.…”