Pseudo-ductility in intermingled carbon/glass hybrid composites with highly aligned discontinuous fibres

Abstract

The aim of this research is to manufacture intermingled hybrid composites using aligned discontinuous fibres to achieve pseudo-ductility. Hybrid composites, made with different types of fibres that provide a balanced suite of modulus, strength and ductility, allow avoiding catastrophic failure that is a key limitation of composites. Two different material combinations of high strength carbon/E-glass and high modulus carbon/E-glass were selected. Several highly aligned and well dispersed short fibre hybrid composites with different carbon/glass ratios were manufactured and tested in tension in order to investigate the carbon ratio effect on the stress-strain curve. Good pseudo-ductile responses were obtained from the high modulus carbon/E-glass composites due to the fragmentation of the carbon fibres. The experimental results were also compared with an analytical solution. The intermingled hybrid composite with 0.25 relative carbon ratio gave the maximum pseudo-ductile strain, 1.1%, with a 110 GPa tensile modulus. Moreover, the initial modulus of the intermingled hybrids with 0.4 relative carbon ratio is 134 GPa, 3.5 times higher than that of E-glass/epoxy composites. The stress-strain curve shows a clear "yield point" at 441 MPa and a well dispersed and gradual damage process

Modelling hybrid effects on the stiffness of aligned discontinuous composites with hybrid fibre-types

“…with intimate intermingling of fibre-types), and extends further the ability to tailor the properties of composites in terms of stiffness, strength or toughness [1][2][3]. Hybrid discontinuous composites have already been manufactured [2][3][4][5] and confirmed the advantages listed previously; however, "hybrid effects" can be observed in the experimental data of hybrid discontinuous composites, not only in the measured strength and failure strain, but also on the stiffness [2][3][4]6].…”

“…Uppercase roman variables E Young's modulus κ stress factor (Table 1) λ characteristic coefficient (Table 1 This paper aims to predict accurately the Young's modulus of hybrid discontinuous composites, capturing the corresponding hybrid effect which can be observed in recent literature [2][3][4]. Section 2 presents the model development for brick-and-mortar composites, composed of successive layers of linear-elastic inclusions or "bricks" (hereafter named platelets) of high and low Young's moduli, embedded in a linearelastic soft matrix phase (or "mortar") ( Fig.…”

“…The specimens were manufactured through the HiPerDif method [2,3], and the specifications of the hybrid discontinuous composites are given in Table 3; the overall fibre volume fraction was estimated to be 30 − 35%, and therefore predictions are plotted for these two values.…”

Mechanical performance of hybrid thermoset composites: Effects of matrix and reinforcement hybridization

“…In short, much could be done to improve the toughness and durability of FRPCs with a hybrid resin matrix. On the other hand, hybridization of the reinforcement is a keenly investigated subject in the case of thermoplastic [24,25] and thermoset matrix FRPCs [26][27][28][29][30][31][32][33]. These studies mainly focused on the enhancement of mechanical properties of thermoset matrix FRPCs but hybrid reinforcement also resulted in improved energy absorption and reduced delamination.…”

Orientation-dispersed pseudo-ductile hybrid composite laminates – A new lay-up concept to avoid free-edge delamination

“…Showing a gradual failure, a higher toughness and pseudo-ductility are other potential advantages of hybrids compared to brittle non-hybrid composites if they are well designed [4,7,11e15]. Mixing the fibres can be done in different levels such as intermingled continuous fibres [16], intermingled aligned short fibres [17], interlayer or sandwiched layers [18] and intralayer [19]. Glass/carbon [4,13,18],carbon/carbon [20e22] and polymer fibre/carbon [19,23] are some of the common material combinations used in hybrid composites.…”