Manufacturing Process Of Fibre-reinforced Composites Research Articles

Numerical Investigation of the Magnetic Alignment of Fe-Co-Coated Single Reinforcement Fibers

Fiber-reinforced composites are progressively more used in a variety of industrial applications. In recent years, carbon fiber-reinforced plastics have become increasingly popular, particularly in the aerospace sector because they offer outstanding mechanical properties combined with low weight. However, the orientation and distribution of the fibers have a significant effect on the mechanical and physical properties of the composite materials. Using conventional manufacturing technologies, it is not always technologically possible to adjust the fiber orientation to the load direction. One possible approach to targeted fiber alignment is the combination of classical manufacturing processes with a superimposed alignment mechanism so that the fibers can be oriented according to the load during component manufacturing. In this context, the orientation and distribution of short and long fibers through an external magnetic field seem to be well-suited to be integrated into the conventional manufacturing process of fiber-reinforced composites. Therefore, the generally non-magnetic reinforcement fibers, e.g. carbon or glass fibers, need to be modified or coated with magnetic materials. In this paper, carbon fibers coated with an iron-cobalt alloy are prepared by electrodeposition for the validation of simulation models developed in previous studies. Furthermore, numerical studies are presented in regard to the orientation of such fibers in polymeric matrices. Thus, simulative investigations of the orientability of coated carbon fibers in polymeric materials are shown and the works provide an important reference for future studies of fiber orientation and alignment using magnetic fields.

Real-time cure behaviour monitoring of polymer composites using a highly flexible and sensitive CNT buckypaper sensor

In this study, we developed a buckypaper (BP) composed of a mono-dispersion of multi-walled carbon nanotubes (MWCNTs) via a spray-vacuum filtration method. This highly flexible and sensitive carbon nanotube buckypaper (MWNCTs-BP) sensor can be integrated into complex curved surfaces and at critical stress areas to monitor the dynamic manufacturing process of fibre-reinforced composites in real time. A dynamic heating cure cycle and two revised cure cycles were designed to study the response of the resistance of the buckypaper to resin phase changes during the composite manufacturing process. Dynamic mechanical analysis (DMA) was performed to obtain the cure behaviour of a glass fibre/epoxy composite as a baseline to compare with the MWCNTs-BP sensor output. The experimental results show that the cure behaviour of epoxy/glass composites can be effectively monitored by the relative resistance change of the BP sensor embedded in the composite laminate. The MWCNTs-BP shows that the lowest viscosity point and gelation point of the composite resin were at 78 °C and 125 °C during the dynamic heating cure cycle, which is consistent with the DMA results. The lowest viscosity and gelation point can also be accurately obtained during the revised cure cycles. The MWCNTs-BP system has great potential as a sensor to establish and optimize manufacturing processes and to improve the cure quality of fibre-based resin composites.

Fibre prestressed polymer-matrix composites: a review

This article reviews the literature studies based on improving the mechanical properties of fibre-reinforced composites using fibre-prestressing method. The idea is characterized by pretensioning the fibres either elastically or viscoelastically prior matrix curing. The beginnings of the studies in this field were focused on reducing fibre waviness and breaking the weaker fibres by pretensioning the fibres to a relatively high stress level prior moulding process. In the last three decades, the concept of fibre prestressing had been developed to include its ability to reduce the effect of undesired residual stresses existence accompanying manufacturing process of fibre-reinforced composites. The main advantage of fibre prestressing method is to generate a desired and controlled residual stress state within the matrix in order to obstruct the initiation and propagation of cracks. Various techniques of fibre prestressing have been reviewed to show their scope of applications, developments and limitations. Therefore, the findings drawn from this review can be used for further studies in the field of fibre prestressed composites in order to select the most suitable methodology and develop it to fit the manufacturing process requirements towards a production of high-performance composites without a considerable additional cost.

VaRTM process of composites using porous mold

This paper introduces Porous Mold Process (PMP) as a reliable low-cost manufacturing process of fiber-reinforced composites. PMP using porous aluminum is applied to the vacuum-assisted resin transfer molding (VaRTM) process of carbon fiber reinforced plastics (CFRPs). Experimental evaluation on resin infusion behavior and quality and mechanical properties of the cured plates is performed with varying the dimensions of the plates. The results show that quality and mechanical properties of the cured plates using PMP are satisfactory, stable, and almost independent of plate dimensions. It is concluded that PMP provides a reliable and knowhow-less resin infusion process of composite materials.

ポーラス型を用いたVaRTM複合材成形

This paper introduces Porous Mold Process (PMP) as a reliable low-cost manufacturing process of fiber-reinforced composites. PMP using porous aluminum is applied to the vacuum-assisted resin transfer molding (VaRTM) process of carbon fiber reinforced plastics (CFRP). Experimental evaluation on resin infusion behavior and quality and mechanical properties of the cured plates is performed with varying the dimensions of the plates. The results show that quality and mechanical properties of the cured plates using PMP are satisfactory, stable, and almost independent of plate dimensions. It is concluded that PMP provides a reliable and knowhow-less resin infusion process of composite materials.