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  • Open Access

    ABSTRACT

    Numerical modeling of resin film infusion process with compaction and its application

    Duning Li, Yufeng Niei?a, Xuemei Zhou, Li Cai

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 75-76, 2011, DOI:10.3970/icces.2011.019.075

    Abstract In this study, the efficient discrete model including the resin infusion and the fiber compaction is developed to simulate the RFI (resin film infusion) process. The non-linear governing equations are derived by the Darcy's law, the Terzaghi's law and the continuity equations. The finite element method and the finite difference method are used to discretize the proposed equations, and the VOF method is used to track the filling front. Compared with the analytical results of Park, our numerical results agree well with them. Furthermore, we analyze the RFI process of BMI/G0814, and simulate the resin More >

  • Open Access

    ARTICLE

    Numerical Modeling of Resin Film Infusion Process with Compaction and Its Application

    Duning Li1, Yufeng Nie1,2, Xuemei Zhou1, Li Cai1

    CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 149-166, 2011, DOI:10.3970/cmes.2011.072.149

    Abstract In this study, the efficient discrete model including the resin infusion and the fiber compaction is developed to simulate the RFI (resin film infusion) process. The non-linear governing equations are derived by the Darcy's law, the Terzaghi's law and the continuity equations. The finite element method and the finite difference method are used to discretize the proposed equations, and the VOF method is used to track the filling front. Compared with the analytical results of Park, our numerical results agree well with them. Furthermore, we analyze the RFI process of BMI/G0814, and simulate the resin More >

  • Open Access

    ARTICLE

    CHARACTERIZATION OF THE RHEOLOGY AND CURE KINETICS OF EPOXY RESIN WITH CARBON NANOTUBES

    R. J. Johnson, R. Pitchumani

    Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-9, 2010, DOI:10.5098/hmt.v1.1.3007

    Abstract Much research is currently being performed with carbon nanotube additives to neat resin systems to enhance properties such as thermal and electrical conductivity, strength, modulus and damping. Fabrication of parts based on carbon nanotube filled resin systems requires information on their cure kinetics and rheology, which has been relatively less studied so far. This work presents an extensive experimental study that systematically characterizes the cure kinetics and viscosity as a function of degree of cure and temperature of EPON 815C/EPICURE 3274 epoxy resin system laden with carbon nanotubes. Studies are conducted to determine the effects More >

  • Open Access

    ARTICLE

    Generalized Stress Intensity Factors for Wedge-Shaped Defect in Human Tooth after Restored with Composite Resins

    Kyousuke Yamaguchi1, Nao-Aki Noda2, Ker-Kong Chen3, Kiyoshi Tajima3, Seiji Harada1, Xin Lan1

    Structural Durability & Health Monitoring, Vol.5, No.3, pp. 191-200, 2009, DOI:10.3970/sdhm.2009.005.191

    Abstract Wedge-shaped defects are frequently observed on the cervical region of the human tooth. Previously, most studies explained that improper tooth-brushing causes such defects. However, recent clinical observation suggested that the repeated stress due to occlusal force may induce the formation of these wedge-shaped defects. In this study, a two-dimensional human tooth model after a wedge-shaped defect is restored with the composite resin is analyzed by using the finite element method. To obtain the intensity of the singular stress accurately, a method of analysis is discussed for calculating generalized stress intensity factors, which control the singular More >

  • Open Access

    ARTICLE

    Effect of Gas Phase Nitration on Poly(methyl methacrylate) (PMMA) Based Ion Exchange Resins

    Shishir Sinha1, Vinay Kumar2

    FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.3, pp. 297-312, 2009, DOI:10.3970/fdmp.2009.005.297

    Abstract High-capacity ion exchange resins based on Poly Methyl Methacrylate (PMMA) was developed during this study having higher mechanical strength, stable and, hydrophilic in nature compared to Poly styrene (PS) based systems. PMMA was cross-linked by Di Vinyl Benzene (DVB) to get macro porous PMMA-DVB resins by suspension polymerization. PMMA-DVB resins were surface modified by nitration followed by amination under appropriate temperature conditions. Change in the color of resin from white to pale yellow and pale yellow to golden yellow as well as characteristic peaks of NO2at 700 cm-1and 1400 cm-1and 3100-3200 cm-1for NH2group in FTIR More >

  • Open Access

    ARTICLE

    Modeling of Moisture Diffusion in Heterogeneous Epoxy Resin Containing Multiple Randomly Distributed Particles Using Hybrid Moisture Element Method

    De-Shin Liu1, Zhen-Wei Zhuang1,2, Cho-LiangChung3, Ching-Yang Chen4

    CMC-Computers, Materials & Continua, Vol.13, No.2, pp. 89-114, 2009, DOI:10.3970/cmc.2009.013.089

    Abstract This paper employs a novel numerical technique, designated as the hybrid moisture element method (HMEM), to model and analyze moisture diffusion in a heterogeneous epoxy resin containing multiple randomly distributed particles. The HMEM scheme is based on a hybrid moisture element (HME), whose properties are determined by equivalent moisture capacitance and conductance matrixes calculated using the conventional finite element formulation. A coupled HME-FE scheme is developed and implemented using the commercial FEM software ABAQUS. The HME-FE scheme is then employed to analyze the moisture diffusion characteristics of a heterogeneous epoxy resin layer containing particle inclusions. The… More >

  • Open Access

    ABSTRACT

    Computational Environment for the Multiscale, Multi-Physics Resin Transfer Molding Process

    B. J. Henz1, D. R. Shires2

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.7, No.1, pp. 13-18, 2008, DOI:10.3970/icces.2008.007.013

    Abstract The capability to predict the residual stresses induced during the manufacturing process in composite components is necessary for the timely fielding of new combat systems. At the U.S. Army Research Laboratory we have developed a computational environment to model the resin flow, heat transfer, curing, and residual stresses in composite components manufactured with the resin transfer molding (RTM) process. This computational environment uses object-oriented programming methods to provide model coupling capabilities and access to high performance computing assets. In this paper we will provide details of the physical models, software, and the validation/verification procedure used More >

  • Open Access

    ARTICLE

    An Integrated Comprehensive Approach to the Modeling of Resin Transfer Molded Composite Manufactured Net-shaped Parts

    N. D. Ngo, K. K. Tamma

    CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.2, pp. 103-134, 2004, DOI:10.3970/cmes.2004.005.103

    Abstract In the process modeling and manufacturing of large geometrically complex structural net-shaped components comprising of fiber-reinforced composite materials by Resin Transfer Molding (RTM), a polymer resin is injected into a mold cavity filled with porous fibrous preforms. The overall success of the manufacturing process depends on the complete impregnation of the fiber preform by the polymer resin, prevention of polymer gelation during filling, and subsequent avoidance of dry spots. Since the RTM process involves the injection of a cold resin into a heated mold, the associated physics encompasses a moving boundary value problem in conjunction More >

  • Open Access

    ARTICLE

    A Real-Coded Hybrid Genetic Algorithm to Determine Optimal Resin Injection Locations in the Resin Transfer Molding Process

    R. Mathur1, S. G. Advani2, B. K. Fink3

    CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.5, pp. 587-602, 2003, DOI:10.3970/cmes.2003.004.587

    Abstract Real number-coded hybrid genetic algorithms for optimal design of resin injection locations for the resin transfer molding process are evaluated in this paper. Resin transfer molding (RTM) is widely used to manufacture composite parts with material and geometric complexities, especially in automotive and aerospace sectors. The sub-optimal location of the resin injection locations (gates) can leads to the formation of resin starved regions and require long mold fill times, thus affecting the part quality and increasing manufacturing costs. There is a need for automated design algorithms and software that can determine the best gate and… More >

  • Open Access

    ARTICLE

    Non-Isothermal Three-Dimensional Developments and Process Modeling of Composites: Flow/Thermal/Cure Formulations and Experimental Validations

    N. D. Ngo, K. K. Tamma1

    CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 57-72, 2000, DOI:10.3970/cmes.2000.001.359

    Abstract In the process modeling via Resin Transfer Molding (RTM) for thick composite sections, multi-layer preforms with varying thermophysical characteristics across the different layers, or for geometrically complex mold geometries with varying thicknesses, the assumption of a thin shell-like geometry is no longer valid. The flow in the through thickness direction is no longer negligible and current practices of treating the continuously moving flow front as two-dimensional and the temperature and cure as three-dimensional are not representative of the underlying physics. In view of these considerations, in the present study, the focus is on the non-isothermal… More >

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