Structural influences of two-dimensional and three-dimensional carbon/epoxy composites on mode I fracture toughness behaviors with rate effects on damage evolution

Abstract

This paper reports the mode I interlaminar fracture toughness and fracture mechanisms of two-dimensional (2D) plain woven composite and three-dimensional (3D) angle-interlock woven composite. The fracture toughness behaviors were tested with double cantilever beam method at the different loading rates from 0.5 to 100 mm/min. Critical strain energy release rate was calculated to compare the difference between the 2D and the 3D woven composites. The fractographs were photographed with scanned electronic microscopy and optical microscopy to show the fracture morphologies. We found that the 3D angle-interlock woven composite has high fracture toughness than that of 2D woven composite. The binder yarns resist the crack initiation and propagation to increase the fracture toughness. While the lower in-plane stiffness of the 3D woven composites should be considered fully for designing the 3D woven composites.

Mode I fracture toughness of fiber-reinforced polymer composites: A review

“…The performance of textile fibers varies depending on their architecture when used as reinforcement in composites. Hence, mechanical characterization in different structural forms [13,47–49], under several static and dynamic loading situations, is the area of interest in recent years.…”

“…In fibre-reinforced composites, the intrinsic mechanisms are structural voids [57], material dislocation [58] or debonding [59,60] generated during manufacture or in-service. The shielding mechanism, also known as external mechanism, results from the closure traction between crack faces in the crack opening due to unbroken fibres or yarns and by deflection of crack path [13,61]. Extrinsic mechanisms give rise to resistive curve (R-curve) behaviour and thus, increase the force required for crack growth [13,28,62].…”

“…Since, there has been an ever-increasing demand for composite materials and new materials are being introduced in the market frequently, so it is challenging to assess their properties in order to forecast service life and failure behaviors. The performance evaluation of the advanced reinforcing fibers (glass [11], carbon [12,13], Kevlar [14,15] and PBO (poly(p-phenylene-2, 6-benzobisoxazole) [16,17] fibers) and resins (Epoxy [18–21], vinyl ester [11], polyimide (PI) [22] and cyanate ester [23]) in final composite is necessary for their safe application.…”

“…Compared to other damage categories, delamination evolution is a dominant life-limiting failure mode for composite structures [13,24–28]. It may be introduced either during manufacturing or caused by damaging events during service, for example, impact damage [29,30], large hailstones [31,32] and bird strike events [33,34], thus, hampering structural integrity and durability [35,36].…”

“…Fracture toughness depends on many factors. Many researchers reported that in FRPCs, the performance of fibers depends on the reinforcement's architecture [13,28,40], which is discussed in the next sections. Hence, structural effects of reinforcement as well as effects of other factors (manufacturing process, loading type, loading rate and temperature) on interlaminar fracture toughness are worth studying.…”