Neural Network Based Control of Preform Permeation in Resin Transfer Molding Processes With Real-Time Permeability Estimation

2000 ◽  
Author(s):  
David Nielsen ◽  
Ranga Pitchumani
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Resin Transfer Molding ◽  
Local Pressure ◽  
Transfer Molding ◽  
Model Based ◽  
Rtm Process ◽  
Virtual Sensing ◽  
Intelligent Model ◽  
Injection Pressures

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.

scholarly journals Embedded Based Real-Time Monitoring in the High-Pressure Resin Transfer Molding Process for CFRP

2019 ◽  
Vol 9 (9) ◽  
pp. 1795 ◽  
Author(s):  
Kim ◽  
Kim ◽  
Hwang ◽  
Kim
Keyword(s):  
High Pressure ◽  
Real Time ◽  
Process Monitoring ◽  
High Speed ◽  
Resin Transfer Molding ◽  
Time Signal ◽  
Process Variables ◽  
Molding Process ◽  
Transfer Molding ◽  
Rtm Process

Carbon Fiber Reinforced Plastics (CFRP) is a material developed for its high strength and light weight in a broad variety of industries including aerospace, automotive, and leisure. Due to the rapid molding cycle time, high-pressure resin transfer molding (HP-RTM) processes are prone to molding defects and susceptible to various process variables such as the resin injection rate, pressure and temperature in the mold, vacuum, end-gap, pressing force, and binder. In recent years, process monitoring technology with various sensors has been applied to stabilize the HP-RTM process and control process variables. The field-programmable gate array (FPGA) based embedded monitoring system proposed in this study enabled high-speed real-time signal processing with multiple sensors, namely pressure, temperature, and linear variable differential transformer (LVDT), and proved feasibility in the field. In the HP-RTM process, the impregnation and curing of the resin were predicted from the cavity pressure and temperature variations during the injection and curing stages. In addition, the thickness of the CFRP specimen was deduced from the change in the end-gap through the detection of the LVDT signal. Therefore, the causes of molding defects were analyzed through process monitoring and the influence of molding defects on the molding quality of CFRP was investigated.

Using Computer Simulation as a Process Design Tool for Resin Injection Pultrusion (RIP)

2000 ◽  
Author(s):  
Zhongman Ding ◽  
Shoujie Li ◽  
L. James Lee ◽  
Herbert Engelen
Keyword(s):  
Modeling And Simulation ◽  
Process Design ◽  
Resin Transfer Molding ◽  
Transfer Molding ◽  
Pultrusion Process ◽  
Rtm Process ◽  
Resin Impregnation ◽  
Heating Section ◽  
Resin Injection ◽  
Resin Injection Pultrusion

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.

scholarly journals COMPUTATIONAL MODELING OF RTM AND LRTM PROCESSES APPLIED TO COMPLEX GEOMETRIES

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 ◽  
...  
Keyword(s):  
Porous Medium ◽  
Flow Behavior ◽  
Resin Transfer Molding ◽  
Three Dimensional ◽  
Complex Geometries ◽  
Resin Flow ◽  
Transfer Molding ◽  
Rtm Process ◽  
General Terms ◽  
Filling Time

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.

Sliding Wear and Friction Properties of Stitched RTM Base Carbon–Carbon Composites

2005 ◽  
Author(s):  
M. K. Surappa ◽  
Kunigal N. Shivakumar
Keyword(s):  
Sliding Wear ◽  
Resin Transfer Molding ◽  
Carbon Composites ◽  
Wear Rates ◽  
Transfer Molding ◽  
Rtm Process ◽  
Composite Fabrication ◽  
Wear And Friction ◽  
Pin On Disc ◽  
Set Up

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.

Uncertainty Modeling of Residual Stress Development in Polymeric Composites Manufactured With Resin Transfer Molding Process

2007 ◽  
Author(s):  
Kuang-Ting Hsiao
Keyword(s):  
Residual Stress ◽  
Resin Transfer Molding ◽  
Parametric Uncertainty ◽  
Polymeric Composite ◽  
Cure Kinetics ◽  
Polymeric Composites ◽  
Molding Process ◽  
Stress Development ◽  
Transfer Molding ◽  
Rtm Process

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.

Preparation and Properties of a Novel Water Soluble Core Material for the Resin Transfer Molding Process

2011 ◽  
Vol 306-307 ◽  
pp. 844-847
Author(s):  
Quan Zhou Li ◽  
Xiao Qing Wu
Keyword(s):  
Compressive Strength ◽  
Resin Transfer Molding ◽  
Water Soluble ◽  
Core Material ◽  
Molding Process ◽  
Transfer Molding ◽  
The Core ◽  
Rtm Process ◽  
Binder Solution ◽  
Core Materials

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.

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