This paper investigates comprehensive knowledge regarding joining CFRP and aluminium alloys in available literature in terms of available methods, bonding processing and mechanism and properties. The ...methods employed comprise the use of adhesive, self-piercing rivet, bolt, clinching and welding to join only CFRP and aluminium alloys. The non-thermal joining methods received great attention though the welding process has high potential in joining these materials. Except adhesive bonding and welding, other joining methods require the penetration of metallic pins through joining parts and therefore, surface preparation is unimportant. No model is found to predict the properties of jointed structures, which makes it difficult to select one over another in applications. The choice of bonding methods depends primarily on the specific applications. The load-bearing mechanism of bolted joints is predominantly the friction that is the first stage resistance. Hybrid joints performance is enhanced by combining rivets, clinch or bolts with adhesives.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Carbon fibre and carbon fibre reinforced polymer matrix composites (CFRPs) are important lightweight materials for aerospace, automotive, rail transport, infrastructure, and renewable energy ...applications. This paper provides a comprehensive review on the history of carbon fibres and carbon fibre composites, the current global CFRPs consumption, and trends for future developments in the aerospace, wind turbine, automotive, pressure vessels, sports and leisure, and construction sectors. The history of carbon fibres and CFRPs is discussed over four representative periods including their early development (1950–60's), growth of carbon fibre composites industry (1970–80's), major adoption of carbon fibre composites (the first wave, 1990–2000's), and expanded use of carbon fibre composites (the second wave, 2010's and beyond). Despite a 37% decline of carbon fibre consumption in the aerospace industry in 2021 caused by COVID-19, the global CFRP demand was around 181 kt which more than doubled its value in 2014. There is tangible projected increase over the next five years and the demand for CFRPs is expected to reach 285 kt in 2025, mainly attributed from the fast expansion of non-aerospace industries such as the wind energy sector. Lower cost carbon fibres (e.g., large tow) and associated manufacturing technologies are continually evolving. Finally, the implications of emerging materials and manufacturing methods in conjunction with recycling and reuse for carbon fibre composites are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Soft robotics is an emerging research field that uses deformable materials or structures to fabricate compliant and adaptable systems through simple integrated mechanisms, thereby, enabling ...biomimetic behaviour. The Venus flytrap has the characteristics of excellent responsiveness and deformability, making it a promising inspirational model for the development of soft robotics. This paper presents a novel robotic gripper that mimics the trapping motion of the Venus flytrap. This gripper was implemented by exploiting a combination of bistable anti-symmetric shells and magnetic actuation. Two cylindrical shells constructed from carbon-fibre-reinforced polymer act as compliant fingers that can transform between two stable configurations based on external actuation. An applied clamped boundary condition reduces the actuation force required to trigger the morphing process. A novel non-contact magnetic actuation method with excellent responsiveness is proposed to actuate the compliant finger. The robotic gripper is designed to be lightweight and compact with high gripping force. Experiments and simulations were performed to analyse the gripping motion and measure the actuation force. The width of the clamped edge is the main factor influencing gripper performance as it relates to actuation force. The results of our analysis demonstrate that the proposed flytrap-inspired design with a bistable structure can be used to implement a novel robotic gripper controlled by a magnetic field.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The capability to accurately analyse the response of multi-directional composite laminates during impact events is of high importance for the design of lightweight aircraft structures. In this work, ...both experimental and numerical analyses are performed covering a large design-space of laminates for all aspects from on-set of damage and barely visible impact damage up to clearly visible impact damage and full penetration of the laminates. The impact tests are simulated using a sophisticated three-dimensional continuum damage model, combined with an automated meso-scale model generation algorithm for ply-by-ply, material/fibre-aligned meshing of laminated composite coupons. To assess the accuracy of the predictions, an extensive validation test program of several configurations and impact energies has been performed, thus demonstrating that the simulations are capable of accurately predicting the damage and failure mechanisms under low-velocity impact loading. Not only the evolution of impact loads and energy dissipated are numerically analysed, but the competition of the dominant failure mechanisms from low impact energy and full penetration cases are also macroscopically replicated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The patterned surface of CFRP created by autoclave processing can be useful in surface pre-treatment and adhesive bonding.•Plasma on CFRPs is useful but grit blasting on alloys may be insufficient ...due to lacking in activation of surface chemistry.•In hybrid joining, the dissimilarity of the two adherends will affect joint strength.•The joints using aerospace adhesive and adherends in this paper showed a very high SLS strength up to 34∼40 MPa.
Manufacturing carbon-fibre reinforced polymer (CFRP) composites via different techniques often leads to contrasting surface topographies. Such differences can affect any subsequent surface pre-treatments that are performed and these can ultimately affect joint strength. In the present work, CFRP adherends made using compression moulding or autoclaving were investigated. Pre-treatment techniques of acetone cleaning, plasma treatment, and grit blasting were studied. It was found that the patterned surfaces which had resulted from the vacuum autoclave moulding resulted in improved joint performance when CFRP substrates were bonded together (homogeneous bonding) compared to joints formed with flatter surfaces following compression moulding. However, when CFRP substrates were bonded to flat aluminium alloy substrates (hybrid bonding) the patterned surfaces resulted in inferior joint performance compared to the flatter CFRP substrates. It is proposed that the dissimilarity of surface topographies on the metal and composite substrates negatively influences the strength of the joint.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•CNT, aramid Pulp, PBO and graphene were used for CFRP toughening.•Low-velocity impact, compression and compression after impact tests were conducted.•The residual compressive strength of reinforced ...CFRPs improved by 8.1–37.8%.•Ultra-thin interlayers had no adverse effects on composite compressive properties.
This study compared the impact properties of carbon fibre reinforced polymer (CFRP) laminates with multiple ultra-thin interlayers of multi-wall carbon nanotubes (CNTs) Aramid pulp (AP) micro/nano-fibres, poly (p-phenylene-2,6-benzobisoxazole) (PBO) fibres (from nano- to micro/nano- and micro-fibres) and multi-layer graphene. The low-velocity impact results showed that the impact damage was notably reduced in all reinforced laminates except the graphene reinforced laminate. Compression after impact tests were conducted on these impacted specimens, showing 8.1–37.8% improvements in residual compressive strength from different micro- and nano-filler reinforcements. While improving the impact resistance, those ultra-thin interlayers with around 1.6 g per square meter of micro/nano-reinforcements were controlled around 8 μm in thickness and did not have any adverse effect on compressive properties of CFRP laminates even without any impact damage.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This paper evaluates the mechanical properties of woven continuous carbon fibre composites printed by additive manufacturing (AM). Comparison mechanical test studies (tensile, flexural and fatigue) ...were carried out with two nonwoven AM printed composites (unidirectional and multidirectional fibres), along with those of both a woven composite, as well as a composite reinforced using chopped carbon fibres. Compared with the 17 MPa tensile strength obtained for the chopped fibre composite, the average strength of unidirectional (nonwoven), multidirectional (nonwoven) and woven fibre composites were 39, 13 and 19-fold higher, respectively. The tensile strength of the woven composites was 52% lower than that attained by the unidirectional (nonwoven) fibre composites; and 38% higher than the multidirectional (nonwoven) fibre composites. A comparison was also made between the flexural and fatigue performance of the unidirectional (nonwoven) and woven fibre composites. The flexural strength of the latter was approximately 39% lower than the nonwoven composites, however, the load bearing capacity of woven fibre was superior. This performance difference was supported by the fatigue testing results. At 70% of maximum tensile load capacity after 2 × 105 cycles, the nonwoven composites failed, while the woven composites continued to perform until a level of 85% of maximum load capacity was reached. The superior fatigue strength of the AM fabricated woven carbon fibre composites, demonstrates their potential for use in high cyclic load applications.
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•A novel AM technique for the fabrication of continuous carbon fibre woven composites.•A superior load bearing capacity of carbon fibre woven composites established.•Woven fibre composites undergo fatigue test (2 × 105 cycles) without catastrophic failure.•A distinct fatigue fracture behaviour established between woven and nonwoven composites.•Woven composites display superior fatigue performance compared to nonwoven.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The increased demand for lightweight high-performance composites has led to search for alternative reinforcement to improve the mechanical performance of conventional structures. Likewise, various ...research initiatives have advocated recycling of construction and demolition wastes and novel technologies to avert their generation. Owing to disadvantages of steel rebar, carbon fibre reinforced polymer (CFRP) was utilized as potential internal reinforcement in recycled concrete beam owing to its lightweight, non-corrosiveness, high-stiffness-to-weight ratio and flexibility. Our study revealed significant improvement in the mechanical performance and efficiency which is controlled by the fibre architecture. The improved mechanical properties was attributed to the Bauschinger strain-reversal effect, made possible by the effective CFRP tensile strength mobilization, its high bonded surface area and interfacial energy as well as the composite action of the multi-layered CFRP reinforcements. The best configuration (N4) revealed by the simplified linear weighted sum optimization method achieved strengthening (load) efficiency of 402.7%, ductility efficiency of 299.7%, fracture toughness efficiency of 567.1% and fracture energy efficiency of 5713.9% compared to the unreinforced control. In addition, CFRP laminate was 3.67–4.9 times more cost-effective than steel rebar in terms of fracture toughness. Therefore, CFRP-reinforced recycled concrete is recommended for cost-effective and sustainable prefabricated concrete structures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The CARALL’s are characterised by high resistance to dynamic load.•The delamination at the interfaces were one of the critical form of damage.•The proposed model can be used to effective examination ...of the FML’s to impact.
Carbon fibre-reinforced aluminium laminates are relatively new fibre-metal laminate materials. Their properties include low density, high resistance and rigidity, and high fatigue strength. This study aimed to evaluate the CARALL response to low-velocity impact, based on experimental tests and numerical analyses of damage initiation and propagation mechanisms. These experimental tests and numerical simulations involved the use of both quantitative and qualitative criteria for assessing the FML damage under dynamic load. It was shown that the mechanism of laminate damage is fairly complex and related to the internal degradation of the composite material with characteristic permanent deflection of the FML. Matrix fractures, carbon-fibre cracking, and delamination were found to be the main modes of damage. The delamination observed at the interfaces of specific multidirectional plies of the composite material and the delamination at the metal-composite interfaces were the critical damage modes of the FMLs. The proposed FEM, including its user-developed failure criteria and cohesive zone, can be used to further examine the influence of various parameters describing FMLs and other adhesive-bonded materials in an effective and reliable manner.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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