Effects of resin pre-coating on interfacial bond strength and toughness of laminar CFRP with and without short aramid fibre toughening

Abstract

The brittle adhesive layer in carbon fiber-reinforced polymer (CFRP) laminates was strengthened by using short aramid fibers in this study. To ensure the feasibility and effectiveness of short aramid fiber interfacial toughening at the interface between the carbon-fiber face sheets, the self-prepared short aramid fibre tissue and the wettability treatment technology with resin pre-coating were applied to enable short aramid fibres to be well embedded in the uneven regions in the CFRP fabrics with fibres oriented at 0° and 90° to form a strong pulling resistance. The ultimate load and the mode I interlaminar fracture toughness have been improved by 75% and 103.9% from the double cantilever beam mode I crack propagation tests, respectively. The reinforcing mechanisms within the “composite adhesive layer” as a result of short aramid fibres are discussed together with detailed scanning electron microscopy observations and comparison test results.

Simultaneously improve the mode II interlaminar fracture toughness, flexural properties, and impact strength of CFRP composites with short aramid fiber interlaminar toughening

“…It showed that the IFT of the EP group decreased by about 6.34% compared to the control group, due to the pure resin increasing the resin‐rich areas in the laminate, providing convenient conditions for crack extension. [ 29 ] The IFT showed a trend of increasing first and then decreasing with the increase of short fiber content. The largest IFT of the laminate was increased by 61.8%, with a short fiber content of 10 g/m 2 compared to the control group.…”

“…[25][26][27] Wang et al [28] used short-cut aramid fiber interlayer toughened CF/EP composites, which resulted in increased, ultimate load and G IC of CFRP laminates, and they used epoxy resin to treat the short fibers and found that it further improved G IC . [29] Mo et al [30] used short ramie fibers to interlayer toughen CF/EP composites. The results showed that the incorporation of short fibers resulted in an effective increase in G IC and G IIC .…”

A Short Review of Recent Progress in Improving the Fracture Toughness of FRP Composites Using Short Fibers

“…To ensure the feasibility and effectiveness of aramid fiber interlaminar toughening CFRP, they adopted wettability treatment technology with resin pre-coating to treat short aramid fiber tissues (6 mm, 24 g/m 2 ), and the peak load and G IC of CFRP were increased by 112%, and 160%, respectively. The pre-coating contributed 37% and 56% improvement, respectively [37]. This explains that the toughening ability of short Kevlar fibers of 3 mm is stronger than 6 mm at the same surface density.…”

Preparation of aramid-based epoxy resin from low-grade aramid

“…As one of the reinforcements of composite materials, aramid ber takes the forms of lament, chopped ber, fabric, and pulp. [2][3][4][5] It is widely used in aerospace, sports equipment, electronic appliances, automobiles, special equipment, and other elds. [6][7][8][9] Aramid ber-reinforced polymer oen refers to the laminated structure prepared by stacking aramid ber and resin matrixes.…”