Simulations of an Infrared Composite Curing Process

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Epoxy resins have several applications in the aerospace and automobile industry. Because of their good adhesive properties, superior mechanical, chemical and thermal properties, and resistance to fatigue and micro cracking, they produce high performance composites. In the technology presented here, the composite is cured in an IR oven which includes halogen lamps. The liquid resin infusion (LRI) process is used to manufacture the composite, whereby liquid resin is infused through a fiber reinforcement previously laid up in a one-sided mold. These epoxy resins release an exothermic heat flux during the curing process, which can possibly cause an excessive temperature in the thickness. Consequently, for the production of high performance composites, it is necessary to know the thermal behavior of the composite during curing. Therefore, IR interactions with the graphite/epoxy system were modeled as a surface radiation transport. In our work, we have studied IR interactions with the composite, which is placed in an IR oven. Using an IR spectrometer Bruker Vertex 70 (1-27 μm), we measured radiative properties and determined the fraction of IR rays absorbed by the composite. Since it is necessary to optimize the manufacturing time and costs and to determine the performance of these composites, the purpose of this study is to model the IR curing of a composite part (carbon fiber reinforced epoxy matrix) in the infrared oven. The work consists in two parts. In the first part, a FE thermal model based on radiosity method was developed, for the prediction of the infrared incident heat flux on the top surface of the composite during the curing process. This model was validated using a reference solution based on ray tracing algorithms developed in Matlab® (In-lab software called Rayheat based on ray tracing algorithms is used to compute the radiative heat flux that impacts the composite). Through the FE thermal model, an optimization study on the percentage power of each infrared heater is performed in order to optimize the incident IR heat flux uniformity on the composite. This optimization is performed using the Matlab® optimization algorithms based on Sequential Quadratic Programming method. In a second part, the optimized parameters set is used in a three-dimensional numerical model which is developed in the finite element commercial software Comsol Multiphysics ™, where the heat balance equation is coupled with the cure kinetic model of the resin. This numerical model allows calculation of the temperature distribution in the composite during curing, which is a key parameter that affects its mechanical properties. In this model, we can predict also the evolution of the degree of cure as function of time. Experimental measurements were used to validate simulations of the whole infrared composite curing process. Keywords: Curing composite, infrared oven, Radiation, Optimization, Epoxy resin, Carbon fibers.

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Periodical:

Key Engineering Materials (Volumes 554-557)

Edited by:

Ricardo Alves de Sousa and Robertt Valente

Pages:

1517-1522

DOI:

10.4028/www.scientific.net/KEM.554-557.1517

Citation:

S. Nakouzi et al., "Simulations of an Infrared Composite Curing Process", Key Engineering Materials, Vols. 554-557, pp. 1517-1522, 2013

Online since:

June 2013

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$38.00

[1] P-I Karkanas, I-K Partridge, Cure modelling and monitoring of epoxy/amine resin Systems II. Network formation and chemoviscosity modelling, Journal of applied Polymer Science, vol. 77, pp.2178-2188, (2000).

DOI: 10.1002/1097-4628(20000906)77:10<2178::aid-app11>3.0.co;2-0

[2] B-C. Chern, T.J. Moon, J.R. Howell, On-line Processing of Unidirectional Fiber Composites Using Radiative Heating: I. Model, J. of Composite Materials, p.1935, (2002).

[3] R. Siegel, J.R. Howell, Thermal Radiation Heat Transfer, Washington DC: Hemisphere Publishing, (1992).

[4] S. Nakouzi, F. Berthet, D. Delaunay, Y. Le Maoult, F. Schmidt,V. Sobotka, Optimization of the incident IR heat flux upon a 3D geometry composite part (Carbon/Epoxy), Key Engineering Materials, Vols. 504-506, pp.1085-1090, (2012).

DOI: 10.4028/www.scientific.net/kem.504-506.1085

[5] S. Nakouzi , J. Pancrace, F.M. Schmidt, Y. Le Maoult, F. Berthet, Simulations of an Infrared Composite Curing Process, Advanced Engineering Materials, vol. 13, issue 7, pp.604-608, (2011).

DOI: 10.1002/adem.201000344

[6] S. Nakouzi , J. Pancrace, F.M. Schmidt, Y. Le Maoult, F. Berthet, Curing simulation of composites coupled with infrared heating, International Journal of Material Forming, Vol. 3 Suppl 1, p.587 – 590, (2010).

DOI: 10.1007/s12289-010-0838-5

[7] M.F. Cohen, D.P. Greenberg, The hemicube: a radiosity approach for complex environments, Computer graphics, pp.31-40, (1985).

[8] S. Monteix, F.M. Schmidt, Y. Le Maoult, G. Denis and M. Vigny, « Recent Issues In Preform Radiative Heating Modeling» in Proceeding of the 17th International Conference of Polymer Processing Society, (2001).

[9] M.E. Ryan and A. Dutta , Kinetics of Epoxy Cure: A Rapid Technique for Kinetic Parameter Estimation. Polymer , pp.203-206, (1979).

DOI: 10.1016/0032-3861(79)90222-2

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