Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
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Study on the Prediction of Dimension Variation due to the Temperature Rises of the Composite Material and Box Beam Type Mold Steel

복합재료를 이용한 박스빔 형태 금형의 온도상승에 따른 치수 변화 예측에 관한 연구

  • Received : 2017.10.18
  • Accepted : 2018.02.06
  • Published : 2018.02.28
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Abstract

Composite material and mold steel can be expanded differently with the temperature gradients during the forming process because their coefficients of thermal expansions are not the same. Therefore, in order to manufacture the product with accuracy, it is necessary to verify that the forming pressure on the surface of the composite material is maintained to the required level from the material supplier. In this paper, the pressure between the composite material and mold due to the temperature difference was predicted by finite element analysis and the accuracy of predicted value was verified by measuring the thermal expansions of mold steel by the ruler. The predicted value by finite element analysis is closely in agreement with one by the experiment within the required tolerance value of ${\pm}0.05mm$.

복합소재와 금형강 간에는 열팽창계수의 차이로 인하여 성형 과정 중의 온도 구배에 따라 다른 열팽창길이를 갖는다. 따라서 금형 내에 복합소재를 삽입하여 성형을 하는 경우 복합소재의 표면에 작용하는 압력이 소재의 업체에서 추천하는 성형 압력을 유지하는지를 확인할 필요성이 있다. 본 연구에서는 온도의 차이에 따른 복합소재와 금형 사이의 압력을 유한요소해석법을 사용하여 예측하였으며 열팽창에 따른 금형의 길이를 측정함으로써 해석의 정확성을 검증하였다. 각 온도에서의 해석과 실험값의 차이로써 매우 근사한 값을 얻을 수 있었으며, 틈새 예측 값의 목표치인 ${\pm}0.05mm$ 안에 들어오는 것을 확인하였다. 이를 통하여 복합소재에 작용하는 압력을 추정한 해석값이 신뢰할 수준임을 알 수 있었다.

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References

  1. Choi G.H., Han C.W., and Lee S.R., "The Study on the Development of Composite Robot Hand for TFT-LCD Glass Transport," Transactions of the Korean Society of Mechanical Engineers A, Vol. 26, No. 7, 2002, pp. 1357-1365. https://doi.org/10.3795/KSME-A.2002.26.7.1357
  2. Kim D.I., and Chang, S.H., "Parametric Study on the Design of Sandwich Beams and Plates for Machine Tool Structures," Journal of the Korean Society of Manufacturing Technology Engineers, Vol. 15, No. 1, 2006, pp. 39-48.
  3. Oh, J.H., Lee, D.G., and Kim, H.S., "Composite Robot end Effector for Manipulating Large LCD Glass Panels," Composite Structures, Vol. 47, Issues 1-4, 1999, pp. 497-506. https://doi.org/10.1016/S0263-8223(00)00013-1
  4. de Oliveira R., Lavanchy, S., Chatton, R., Costantini, D., Michaud, V., Salathe, R., and Manson J.-A.E., "Experimental Investigation of the Effect of the Mold Thermal Expansion on the Development of Internal Stresses during Carbon Fiber Composite Processing," Composites: Part A, Vol. 39, Issue 7, 2008, pp. 1083-1090. https://doi.org/10.1016/j.compositesa.2008.04.011
  5. Choi, S.K., and Park, S.M., "A Study on Thermal Property of Carbon-epoxy Composites," Journal of the Korean Society for Aeronautical and Space Sciences, Vol. 29, No. 5, 2001, pp. 58-66.
  6. Yun, K.J., Kim, P.J., Kim, T.W., and Jeon, E.J., "Analysis of Thermal Deformation in Forming Process of Carbon Fiber Composite Stiffener," Proceedings of 1994 Korean Society for Aeronautical and Space Sciences Spring Conference, Korea, April 1994, pp. 194-198.
  7. Barnes, J.A., Byerly, M.C., LeBouton, M.C., and Zahlan, N., "Dimensional Stability Effects in Thermoplastic Composites - Towards a Predictive Capability," Composites Manufacturing, Vol. 2, No. 3-4, 1991, pp. 171-178. https://doi.org/10.1016/0956-7143(91)90136-5
  8. Yanagimoto, J., and Ikeuchi, K., "Sheet Forming Process of Carbon Fiber Reinforced Plastics for Lightweight Parts", CIRP Annals, Vol. 61, Issue 1, 2012, pp. 247-250. https://doi.org/10.1016/j.cirp.2012.03.129
  9. James M. Gere, Mechanics of Materials, Sixth Edition, Thomson Learning, Inc., 2004.