The role of hybridisation and fibre architecture on the post-impact flexural behaviour of composite laminates

Abstract

Advanced composite materials are widely used in civil and military applications due to their superior specific strength and stiffness. However, they are susceptible to damage during impact loading. In order to improve the impact performance, yarn hybridisation and fibre architecture have been investigated in this study in order to evaluate their influence on the damage tolerance (i.e. post- impact flexural strength) of glass composite laminates. Two types of yarn have been used here, namely, pure glass yarns as a bench-mark and hybrid yarns (glass-polypropylene) to manufacture non-crimp and woven (twill and satin) fabric composites. The composite laminates were then subjected to low-velocity impact tests at various impact energies. Afterwards, post- impact flexural strength has been evaluated with a four-point bending test. It has been observed that the non-crimp and woven hybrid composites laminates displayed smaller damage areas compared to the non-crimp glass composites laminates. In addition, although the hybrid laminates have exhibited lower flexural strength properties than the non-crimp glass laminates, the former has shown higher post-impact flexural strength. Fractography analysis has suggested here that the damage failure modes such as intra-yarn cracks have been produced in the hybrid yarns laminates and intra-yarn and inter-yarn cracks have been produced in hybrid fabric laminates. These damage failures have contributed for absorbing impact energy leading to an enhancement of the damage tolerance of the hybrid laminates.

An investigation of the effect of structural parameters on the impact properties of sandwich-structured shock absorbers

“…The open curves noticeable in the load-deformation graphs (Fig. 3, 5 and 7) of the samples prove that the striker has fully penetrated the samples, that is, full penetration has occurred [32]. This full penetration can also be noticed in damage patterns shown in Fig.…”

Influence of yarn-hybridisation on the mechanical performance and thermal conductivity of composite laminates

“…[12][13][14] Hence, it is important to understand their ability to continue functioning properly after damage events by evaluating their residual strength either compressive or flexural strength after impact tests. [15][16][17][18] Many investigations have demonstrated that the damage tolerance of composite laminates can be improved by adopting different strategies. One of the promising strategies is toughening of the polymer matrix by tuning the polymer chemistry or by incorporating different particles like rubbers, thermoplastics or nano-scale particles.…”

Improving the fracture toughness of glass/epoxy laminates through intra-yarns hybridisation

“…epoxy resin), offers the opportunity for the researchers to enhance the fracture toughness, impact resistance and also to explore the kinetic energy dissipation of these laminates during impact event. 10,[39][40][41] Ramirez et al 42 studied the effect of polyphenylene sulphide non-woven veils on mode-I and mode-II interlaminar fracture toughness of the unidirectional CF/EP laminates. Lee et al 43 investigated the behaviour of the mode-II interlaminar fracture toughness of carbon composite laminates by hybridising carbon fibre with nonwoven tissue (NWT).…”

“…1–3 Nevertheless, these laminates are particularly prone against delamination, which strongly reduces their properties such as the load-bearing capacity, compression strength, toughness, and fatigue life. 4–12 Therefore, the study to enhance the interlaminar fracture toughness of glass fibre laminates has drawn the attention of the designers and composites manufacturers. Delamination or inter-ply separation is the most predominant and crucial failure mechanism in composite laminates.…”