Papers by Keyword: RTM

Abstract: In this paper, a novel Z-direction flowing RTM technology using an in-mold resin distributor has been applied to the “Ex-situ” composites and the process feasibility was evaluated. The effect of injection type on distribution of fiber volume fraction and thermoplastic toughener in the composite were investigated. The results showed that perfect internal quality composite panels could be fabricated via the novel RTM technology and the injection type has some effects on distribution of fiber volume fraction along the thickness direction of the panels. After the injection and curing cycle, the typical bicontinuous phase structures were mainly observed at the interlaminar and also slightly spreading into the fibre beam.

Abstract: RTM is also called resin transfer moulding, it is one of the leading technology in the field of FRP. With the help of FLUENT, a powerful computational fluid dynamics software, we have finished the process simulation of filling the mould. In the process simulation, the flow striker, pressure field and velocity field are clearly showed. And they can describe the process of RTM effectively.

Abstract: Based on the “ex-situ” toughening concept, thermoplastic nylon (PA) nonwoven fabric with high porosity was chosen as the toughening layer, and the interlaminar toughened composites were fabricated via RTM process. Compression strength after impact (CAI) properties were investigated as well as the toughening mechanism. The results indicated that there is no bicontinuous phase structures formed by reaction-induced phase decomposition and inversion. The PA nonwoven fabrics still kept the original structure in composites interlaminar, and formed a macroscopical bicontinuous structure with the matrix resin, which also showed remarkable toughening effect. The CAI value increased from 212MPa to 281MPa.

Abstract: Resin Transfer Moulding (RTM) as it is most known process in the Resin Injections family, is an extensively studied and used processing method. This process is used to manufacture advanced composite materials made of fibres embedded in a thermoset polymer matrix. Fibre reinforcement in RTM processing of polymer composites is considered as a fibrous porous medium regarding its infiltration by the polymer resin. In this sense, the present work aims the computational analysis of a fluid in a porous media for a RTM composite moulding by using the ANSYS CFX^® commercial software. In order to validate the numerical study of the fluid flow in a known RTM system, experiments was carried out in laboratory to characterize the fluid (vegetal oil) flowing into the porous media (0/90 glass fibre woven), were pressure and fibre volume fraction have been fixed. The numerical simulation provides information about volume fraction, pressure and velocity distribution of the phases (resin and air) inside the porous media. The predicted results were compared with the experimental data and its has shown a solid relationship between them.

Abstract: A novel water soluble core material composed of alumina, quartz sand, kaolin, gypsum powder and the solution of binders was prepared. The influence of different mass concentration of Polyethylene Glycol (PEG) binder solution and sodium silicate compounded (SS) binders solution on water soluble performance and compressive strength of the core materials was investigated, respectively. The results show that the compressive strength and solubility rate of the core materials, with the concentration of 30% of SS binders solution, are 1.023MPa and 0.24g/s respectively, which is satisfied for the requirements of Resin Transfer Molding (RTM) process completely.

Abstract: The composite components with irregular shape are often used in many application areas. Normally the formation of the composite components with irregular shape is by laminated technology. However the main problem of laminated composites is that there is a pure resin area between two lays which will degrade the mechanical properties of composite components. Three dimensional (3D) integrated braided composite can overcome this problem. In this paper, the design and manufacture technology of 3D integrated braided composite support with irregular shape were researched, including: braiding technology of 3D braided preform of composite support, the determination of process parameters of resin transfer molding(RTM) for 3D braided composite support, and the design of mold for consolidation of composite support. The compress property and shear property of this composite were investigated. The maximum compress force borne by this composite support is 2.31 kN, which is more than the design value of 1.90 kN and the maximum shear force borne by this composite support is 4.48 kN, which is more than the design value of 4.10 kN. The weight of 3D braided composite support is only 60.27% of the weight of titanium support.

Abstract: This paper presents an experimental investigation on the failure modes of glass fiber reinforced 2D woven fabric with ladder splicing laminate composites. On the basis of [0/0/+45/90/-45/90]s ply sequence, six kinds of laminated performs with different splicing interval lengths which were 4mm, 8mm, 12mm respectively and two different splicing shape which were ladder splicing and double vertical line splicing, and a kind of laminated perform with continuous laminates of 2D glass fiber woven fabric were made. By means of RTM molding technology, the technological parameters of RTM processing were designed as follows: injection temperature was 25°C, injection duration time was 180min and injection pressure was 0.4MPa, the epoxy resin based 2D glass fiber woven fabric RTM laminated specimen were prepared. According to the GB/T 1447-2005 and GB/T 1449-2005standard test method, the failure modes of 2D glass fiber woven fabric laminated RTM specimen were tested. Results show that the failure modes of laminate composites manifest as rapid damage in the form of line inlay mode and wedge shape mode at 4mm interval length condition, and accumulating failure in the form of inlay layer slippage - fiber pulled out mode and fiber fracture - splicing layer deboning mode at 12mm interval length. Otherwise, all fracture position of splicing laminates occurs at the site of splicing line because of the concentration of tensile stress.

Abstract: Resin transfer molding (RTM) is a very important category of low cost fibre reinforcement composite material manufacturing technique. But void which mainly formed at the process of filling and infiltration is able to reduce the performance of products. This paper first introduced how harmful the void is, and then formation theory, finally focus on the technical feature and resent evolution. Numerical simulation is always a mature and efficient research method for this field of investigation. Formerly, scientists also attribute their effort to such investigation, but, at that time, their simulation was 1D or 2D which can not represent the process accurately enough. Therefore the results are not so significant. Recently most studies pay attention to 3D simulation and how factors (such as injection pressure, structure of preform and so on) work. With the development of mathematic theory and simulation software some new numerical simulation methods present itself. Researchers may copy the course of resin’s filling in RTM more integrity to make their relation close to reality. Based on their achievement, the technique of RTM also improved to eliminate void’s emergence. However the real flow of resin is more than complex, more work should be done to avoid it and then set up a controllable industrial production system.

Abstract: During the resin flow of Resin Transfer Molding, the permeability of fiber performs is an important parameter, which reflects the interaction between the resin and fiber. In this paper the Darcy’s law was used as the fundamentals to determine the permeability of fiber performs, an experiment installation was designed, and do some experimental study on the one-dimensional permeability of resin in the multilayer fibrous plaids at a constant flow rate. The installation was designed base on condition of different flow rates and different fiber volumes (or porosity), and compared the results of the permeability of different flow rates. Then analyzed the results, and some content conclusions were obtained.

Abstract: In this paper, the design and manufacture technology of three dimensional(3D) integrated braided composite tube with flange are researched, including: braiding technology of 3D braided preform of tube with flange, the determination of process parameters of resin transfer molding(RTM) for 3D braided composite tube with flange, and the design of mould for consolidation of composite tube with flange. The fiber volume fraction of this component is calculated. The quality of composite tube with flange is good analyzed by ultrasonic A-scan. The maximum compressive force borne by composite tube flange is 56.65 kN, which has met the need of usage of 38 kN. The research result will provide a good way for designing and manufacturing high performance 3D integrated braided composite components with irregular shape.