Monitoring of resin flow in the resin transfer molding (RTM) process using point-voltage sensors

2007 ◽  
Vol 67 (3-4) ◽  
pp. 367-379 ◽  
Author(s):  
Murat Danisman ◽  
Goker Tuncol ◽  
Alper Kaynar ◽  
E. Murat Sozer
2012 ◽  
Vol 11 (1-2) ◽  
pp. 93 ◽  
Author(s):  
J. Da S. Porto ◽  
M. Letzow ◽  
E. D. Dos Santos ◽  
S. C. Amico ◽  
J. A. Souza ◽  
...  

Light Resin Transfer Molding (LRTM) is a variation of the conventional manufacturing process known as Resin Transfer Molding (RTM). In general terms, these manufacturing processes consist of a closed mould with a preplaced fibrous preform through which a polymeric resin is injected, filling the mold completely, producing parts with complex geometries (in general) and good finish. Those processes differ, among other aspects, in the way that injection occurs. In the RTM process the resin is injected through discrete points whereas in LRTM it is injected into an empty channel (with no porous medium) which surrounds the entire mold perimeter. There are several numerical studies involving the RTM process but LRTM has not been explored enough by the scientific community. Based on that, this work proposes a numerical model developed in the FLUENT package to study the resin flow behavior in the LRTM process. Darcy’s law and Volume of Fluid method (VOF) are used to treat the interaction between air and resin during the flow in the porous medium, i.e. the mold filling problem. Moreover, two three-dimensional geometries were numerically simulated considering the RTM and LRTM processes. It was possible to note the huge differences about resin flow behavior and filling time between these processes to manufacture the same parts.


2000 ◽  
Author(s):  
David Nielsen ◽  
Ranga Pitchumani

Abstract Variabilities in the preform structure in situ in the mold are an acknowledged challenge to effective permeation control in the Resin Transfer Molding (RTM) process. An intelligent model-based controller is developed which utilizes real-time virtual sensing of the permeability to derive optimal decisions on controlling the injection pressures at the mold inlet ports so as to track a desired flowfront progression during resin permeation. This model-based optimal controller employs a neural network-based predictor that models the flowfront progression, and a simulated annealing-based optimizer that optimizes the injection pressures used during actual control. Preform permeability is virtually sensed in real-time, based on the flowfront velocities and local pressure gradient estimations along the flowfront. Results are presented which illustrate the ability of the controller in accurately steering the flowfront for various fill scenarios and preform geometries.


2000 ◽  
Author(s):  
Zhongman Ding ◽  
Shoujie Li ◽  
L. James Lee ◽  
Herbert Engelen

Abstract Resin Injection Pultrusion (RIP) is a new composite manufacturing process, which combines the advantages of the conventional pultrusion process and the Resin Transfer Molding (RTM) process. It is sometimes referred to the Continuous Resin Transfer Molding (C-RTM) process. The RIP process differs from the conventional pultrusion process in that the resin is injected into an injection-die (instead of being placed in an open bath) in order to eliminate the emission of volatile organic compounds (styrene) (VOC) during processing. Based on the modeling and simulation of resin/fiber “pultrudability”, resin flow, and heat transfer and curing, a computer aided engineering tool has been developed for the purpose of process design. In this study, the fiber stack permeability and compressibility are measured and modeled, and the resin impregnation pattern and pressure distribution inside the fiber stack are obtained using numerical simulation. Conversion profiles in die heating section of the pultrusion die can also be obtained using the simulation tool. The correlation between the degree-of-cure profiles and the occurrence of blisters in the pultruded composite parts is discussed. Pulling force modeling and analysis are carried out to identify the effect on composite quality due to interface friction between the die surface and the moving resin/fiber mixture. Experimental data are used to verify the modeling and simulation results.


Author(s):  
M. K. Surappa ◽  
Kunigal N. Shivakumar

This paper presents wear and friction properties of carbon-carbon composites (CCC) manufactured by resin transfer molding (RTM) process. During composite fabrication thickness stitching was employed to improve inter laminar tension and shear properties. Wear and Friction characteristics of carbon-carbon composites were evaluated using pin-on-disc set up. Results of test indicate that surface of composites having stitches in a perpendicular direction show increase in wear rates with increase in load.


2009 ◽  
Vol 18 (2) ◽  
pp. 135-152 ◽  
Author(s):  
Moon-Kwang Um ◽  
Joon-Hyung Byun ◽  
Isaac M. Daniel

Author(s):  
Kuang-Ting Hsiao

Resin Transfer Molding (RTM) is an advanced process to manufacture high quality thermoset polymeric composites. The quality of the composite depends on the resin infusion stage and the cure stage during the RTM process. The resin curing is a complex exothermic process which involves resin mechanical property evolution, resin volume shrinkage, thermal expansion, heat transfer, and chemical reaction. Since the fibers and resin have many differences in their physical properties, the composite cure stage inevitably introduces the undesired residual stress to the composite parts. As the residual stress could sometimes generate local matrix failure or degrade the performance of the composite, it is important to model and minimize the residual stress. This paper presents a model to predict the residual stress development during the composite cure process. By slightly disturbing the manufacturing parameters such as the mold heating cycle and the cure kinetics of polymer, the variations of residual stress development during the RTM process can be modeled and compared. A parametric uncertainty study of the residual stress development in the polymeric composite manufactured with RTM will be performed and discussed.


2011 ◽  
Vol 306-307 ◽  
pp. 844-847
Author(s):  
Quan Zhou Li ◽  
Xiao Qing Wu

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.


1999 ◽  
Vol 121 (04) ◽  
pp. 58-61 ◽  
Author(s):  
Gale Morrison

This article reviews the advanced resin transfer molding (RTM) process of GKN Westland Aerospace. This process is refined enough, with customized equipment and a proprietary resin binding material, so that hundreds of different aircraft parts that would otherwise be heavier (made of titanium) are being produced for customers that include GE, Pratt & Whitney, Lockheed Martin, and Boeing. GKN is making five-axis, hollow vein, and integrated attachment nodes. It has produced carbon-fiber and resin components as thick as 3½ inches, and designs can combine what were many parts. Depending on the part and desired strength (in the desired directions), the fiber tow is woven in a variety of ways. For strength in mainly one direction, the engineers specify that 75 percent of the tow runs in one direction and just 25 percent of it is used to weave across it, for example. The next step in GKN’s advanced RTM evolution is a unihybrid composite that takes great loads in just one direction and can be made very thick, up to 3½ inches. A slightly less rigorous process has already been licensed, to a company in Mexico that produces a component for the Dodge Viper sports car.


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