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Alfred C Loos - One of the best experts on this subject based on the ideXlab platform.

  • a three dimensional model of the Resin Film Infusion process
    Journal of Composite Materials, 2002
    Co-Authors: Alfred C Loos, D. Rattazzi, R. C. Batra
    Abstract:

    A finite element code, in modular form, has been developed to model the complete three-dimensional Resin Film Infusion (RFI) process. The problem formulation and its analysis incorporate compaction of the anisotropic elastic porous preform, elastic deformations of the tooling components, heat transfer in the Resin, flow of Resin through the preform, cure kinetics of the Resin, and the heat transfer between the tools and the surrounding environment in the autoclave. The inertia effects and the transfer of heat by convection have been neglected. Two techniques, namely the slideline algorithm and a compliant layer interface, are used to model the possible sliding of the tool over the preform at their common interfaces. Weak forms are derived for (a) the initial-boundary-value problem corresponding to the transient thermal problem, (b) the boundary-value problem for the fluid through an elastic porous medium, and (c) the boundary-value problems for the quasistatic deformations of the tooling components and for a partially or fully saturated porous elastic preform. The finite element method is used to solve these equations, and the flow front is located by using a control volume technique. Computed results are presented for a stiffened T-panel and a two-stiffener panel.

  • A Three-Dimensional Model of the Resin Film Infusion Process
    2001
    Co-Authors: Alfred C Loos, D. Rattazzi, R. C. Batra
    Abstract:

    ABSTRACT: A finite element code, in modular form, has been developed to model the complete three-dimensional Resin Film Infusion (RFI) process. The problem formulation and its analysis incorporate compaction of the anisotropic elastic porous preform, elastic deformations of the tooling components, heat transfer in the Resin, flow of Resin through the preform, cure kinetics of the Resin, and the heat transfer between the tools and the surrounding environment in the autoclave. The inertia effects and the transfer of heat by convection have been neglected. Two techniques, namely the slideline algorithm and a compliant layer interface, are used to model the possible sliding of the tool over the preform at their common interfaces. Weak forms are derived for (a) the initial-boundary-value problem corresponding to the transient thermal problem, (b) the boundary-value problem for the fluid through an elastic porous medium, and (c) the boundary-value problems for the quasistatic deformations of the tooling components and for a partially or fully saturated porous elastic preform. The finite element method is used to solve these equations, and the flow front is located by using a control volume technique. Computed results are presented for a stiffened T-panel and a two-stiffener panel. KEY WORDS: Resin Film Infusion, composite manufacturing, textile preform, process modeling

  • Resin Film Infusion rfi process modeling for large transport aircraft wing structures
    2000
    Co-Authors: Alfred C Loos, Aaron C. Caba, Keith W Furrow
    Abstract:

    This investigation completed the verification of a three-dimensional Resin transfer molding/Resin Film Infusion (RTM/RFI) process simulation model. The model incorporates Resin flow through an anisotropic carbon fiber preform, cure kinetics of the Resin, and heat transfer within the preform/tool assembly. The computer model can predict the flow front location, Resin pressure distribution, and thermal profiles in the modeled part. The formulation for the flow model is given using the finite element/control volume (FE/CV) technique based on Darcy's Law of creeping flow through a porous media. The FE/CV technique is a numerically efficient method for finding the flow front location and the fluid pressure. The heat transfer model is based on the three-dimensional, transient heat conduction equation, including heat generation. Boundary conditions include specified temperature and convection. The code was designed with a modular approach so the flow and/or the thermal module may be turned on or off as desired. Both models are solved sequentially in a quasi-steady state fashion. A mesh refinement study was completed on a one-element thick model to determine the recommended size of elements that would result in a converged model for a typical RFI analysis. Guidelines are established for checking the convergence of a model, and the recommended element sizes are listed. Several experiments were conducted and computer simulations of the experiments were run to verify the simulation model. Isothermal, non-reacting flow in a T-stiffened section was simulated to verify the flow module. Predicted infiltration times were within 12-20% of measured times. The predicted pressures were approximately 50% of the measured pressures. A study was performed to attempt to explain the difference in pressures. Non-isothermal experiments with a reactive Resin were modeled to verify the thermal module and the Resin model. Two panels were manufactured using the RFI process. One was a stepped panel and the other was a panel with two 'T' stiffeners. The difference between the predicted infiltration times and the experimental times was 4% to 23%.

  • verification of a simulation model for Resin Film Infusion of complex shaped composite structures
    Journal of Reinforced Plastics and Composites, 1999
    Co-Authors: Aaron C. Caba, R. C. Batra, D. Rattazzi, Alfred C Loos
    Abstract:

    Resin Film Infusion (RFI) has been found to be a cost-effective technique for the fabrication of complex shaped composite parts for primary structural applications. Dry textile preforms are infiltrated, consolidated, and cured in a single step, eliminating the labor to lay-up prepreg tape. The large number of processing variables and the complex material behavior during infiltration and cure make experimental optimization of the RFI process extremely inefficient.The objective of this work was to develop and verify a three-dimensional model to simulate the RFI process. For a specified pressure and temperature cure cycle the code can predict Resin pressure, viscosity and degree of cure, flow front progression, and temperature distribution in the preform and tooling components. The model was divided into submodels which describe Resin flow, heat transfer, and Resin kinetics. A finite element/control volume approach was used to model the flow of the Resin through the preform. Boundary conditions include speci...

  • Resin Film Infusion rfi process simulation of complex shaped composite structures
    Proceedings of the 1996 37th AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference. Part 4 (of 4), 1996
    Co-Authors: Alfred C Loos, John D Macrae, David J Hood, David E Kranbuehl, H B Dexter
    Abstract:

    A 3D model was developed which is used to simulate the RFI manufacturing process of complex shaped composite structures. The model is comprehensive and includes submodels which describe Resin flow, heat transfer, preform compaction, and Resin kinetics during the RFI process. Experiments were performed to characterize the stitched preform and obtain data for verification of the model. In the verification experiment, a complex shaped stitched preform was Resin infiltrated and cured in an instrumented mold which included in situ FDEMS sensors to monitor the flow front position and the state of the Resin cure. Results of the verification experiment indicate that the model can accurately predict the thermal behavior of the preform/tool assembly. The model-predicted wet-out times were higher than the sensor measured values, possibly due to Resin leakage from the ends of the preform. (Author)

Jean-christophe Minni - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of Liquid Resin Infusion (LRI) filling by fringe pattern projection and in situ thermocouples
    Composites Part A: Applied Science and Manufacturing, 2010
    Co-Authors: Peng Wang, Sylvain Drapier, Jérôme Molimard, Alain Vautrin, Jean-christophe Minni
    Abstract:

    Prepregs are not alone suited to the manufacturing of new types of aircraft structural parts that tend to be thicker and have more complex shapes. Direct processes called Liquid Composites Moulding (LCM), like Resin Transfer Moulding (RTM) or Resin Infusion Process (LRI: Liquid Resin Infusion, RFI: Resin Film Infusion) are now available. Particular attention is paid here to LRI process that looks very promising. In order to optimize both the design and manufacturing parameters in LRI processes, a general model to analyze the isothermal fluid flow through highly compressible porous media such as fibrous preforms has been recently proposed [1], [2] and [3]. To validate the model and to improve the knowledge of the LRI process, an experimental approach is proposed. Two different measurement techniques, micro-thermocouple sensors and fringe projection technique, have been used to characterize the process. It appears that results derived from both techniques are in agreement and support the assumption that the Resin flow occurs mainly transversely to the preform plane.

Tan Hua - One of the best experts on this subject based on the ideXlab platform.

  • simulation and analysis of model filling of Resin Film Infusion process
    Materials Science and Technology, 2007
    Co-Authors: Tan Hua
    Abstract:

    Resin Film Infusion(RFI) is a new technique for the manufacture of composite structures.In order to understand the influences of control parameters on the quality of product in mold filling of RFI deeply and to avoid plaque formation and incomplete filling,a control equation is set up based on Darcy's Law,which can describe the flow behavior in mold filling of RFI.The finite element control volume method was chosen to develop a two-dimensional model,which could be used to simulate isothermal infiltration of a hot-melt Resin into a complex shape textile perform.The application of this model was discussed.Results of the simulation were used to forecast the filling time,flow front and pressure distributing.The effect of compaction pressure on the Resin infiltration time was also studied.

  • simulation of the Resin Film Infusion process based on the finite element method
    Journal of Wuhan University of Technology-materials Science Edition, 2006
    Co-Authors: Yang Mei, Yan Shilin, Tan Hua
    Abstract:

    A physically accurate and computationally effective pure finite element method (FEM) was developed to simulate the isothermal Resin infusing process. The FEM was based on conservation of Resin mass at any instant of time and was objective of Resin Film Infusion (RFI) fiber impregnation and mold filling. The developed computer code was able to simulate the Resin infusing visually. A numerical example presented here demonstrated that compared with traditional finite element/control-volume (FE/CV), and FEM was physically accurate and computationally efficient.

  • a numerical simulation of Resin Film Infusion process
    Journal of Wuhan University of Technology, 2005
    Co-Authors: Tan Hua
    Abstract:

    Numerical simulation is an economic and fast selection to investigate the Resin Film Infusion process.In this paper,the flow behavior and cure process of Resin of this technique in complex shape performs were analyzed,and a flow simulation code was compiled on control volume/finite element and pure finite element,respectively.Cure code was developed also.A simulation of an example showed that this code can be used to forecast the filling time,flow front,pressure and temperature distributing,cure degree and the viscosity of Resin at any time of Resin Film Infusion,which would help to optimize the process parameters,control residual stress and improve products quality.

Peng Wang - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of Liquid Resin Infusion (LRI) filling by fringe pattern projection and in situ thermocouples
    Composites Part A: Applied Science and Manufacturing, 2010
    Co-Authors: Peng Wang, Sylvain Drapier, Jérôme Molimard, Alain Vautrin, Jean-christophe Minni
    Abstract:

    Prepregs are not alone suited to the manufacturing of new types of aircraft structural parts that tend to be thicker and have more complex shapes. Direct processes called Liquid Composites Moulding (LCM), like Resin Transfer Moulding (RTM) or Resin Infusion Process (LRI: Liquid Resin Infusion, RFI: Resin Film Infusion) are now available. Particular attention is paid here to LRI process that looks very promising. In order to optimize both the design and manufacturing parameters in LRI processes, a general model to analyze the isothermal fluid flow through highly compressible porous media such as fibrous preforms has been recently proposed [1], [2] and [3]. To validate the model and to improve the knowledge of the LRI process, an experimental approach is proposed. Two different measurement techniques, micro-thermocouple sensors and fringe projection technique, have been used to characterize the process. It appears that results derived from both techniques are in agreement and support the assumption that the Resin flow occurs mainly transversely to the preform plane.

Zuoguang Zhang - One of the best experts on this subject based on the ideXlab platform.