Change of Mechanical Properties of Injection-Molded Glass-Fiber-Reinforced Plastic (GFRP) According to Temperature and Water Absorption for Vehicle Weight Reduction

차량 경량화를 위한 사출성형 유리섬유강화플라스틱의 온도 및 수분 흡수에 따른 기계적 물성 변화

  • Chun, Doo-Man (School of Mechanical Engineering, Univ. of Ulsan) ;
  • Ahn, Sung-Hoon (School of Mechanical and Aerospace Engineering, Seoul Nat'l Univ.)
  • 천두만 (울산대학교 기계공학부) ;
  • 안성훈 (서울대학교 기계항공공학부)
  • Received : 2012.06.25
  • Accepted : 2012.11.08
  • Published : 2013.02.04


Owing to the global energy crisis, studies have strongly focused on realizing energy savings through vehicle weight reduction using light metal alloys or polymer composites. Polymer composites afford many advantages including enabling the fabrication of complex shapes by injection molding, and glass and carbon fibers offer improved mechanical properties. However, the high temperature in an engine room and the high humidity during the rainy season can degrade the mechanical properties of the polymer. In this study, the mechanical properties of injection-molded glass-fiber-reinforced polymer were assessed at a temperature of $85^{\circ}C$ and the maximum moisture absorption conditions. The result showed a 23% reduction in the maximum tensile strength under high temperature, 30% reduction under maximum moisture absorption, and 70% reduction under both heat and moisture conditions. For material selection during the design process, the effects of high temperature and high humidity should be considered.


Injection Molding;Glass Fiber Reinforced Plastics;Mechanical Property;Temperature;Water Absorption


Supported by : 울산대학교


  1. Cole, G. S. and Sherman, A. M., 1995, "Light Weight Materials for Automotive Applications," Materials Characterization, Vol.35, No. 1, pp. 3-9.
  2. Mustafa, K. K., 2008, "Magnesium and its alloys Applications in Automotive Industry," The International Journal of Advanced Manufacturing Technology, Vol. 39, No. 9-10, pp., 851-865.
  3. Shanmughasundaram, P. and Subramanian, R., 2011, "Aluminium - Fly Ash Composites as Light Weight," Materials for Automotive Industry, Paper Number: 2011-28-0009.
  4. Friedrich, K. and Almajid, A. A., 2012, "Manufacturing Aspects of Advanced Polymer Composites for Automotive Applications," Applied Composite Materials, (in print) DOI: 10.1007/s10443- 012-9258-7.
  5. Goede, M., Stehlin, M., Rafflenbeul, L., Kopp, G. and Beeh, E., 2009, "Super Light Car—lightweight Construction Thanks to a Multi-Material Design and Function Integration," European Transport Research Review, Vol. 1, No. 1, pp. 5-10.
  6. Jeon, K. W., Shin, K. B. and Kim, J. S., 2011, "An Evaluation of Fatigue Life and Strength of Lightweight Bogie Frame Made of Laminate Composites," Trans. Korean Soc. Mech. Eng. A, Vol. 35, No. 8, pp. 913-920.
  7. Ko, H. Y., Shin, K. B. and Kim, J. S., 2010, "A Study on Improving the Fatigue Life for a Woven Glass Fabric/Epoxy Laminate Composite Applied to Railway Vehicles," Trans. Korean Soc. Mech. Eng. A, Vol. 34, No. 2, pp. 203-209.
  8. Oka, H., Tabuchi, Y. and Yazawa, H., 2002, "Development of Plastic Pulley for Automotive Air Conditioner Compressor," SAE Technical Paper 2002- 01-0603.
  9. Tho, Y. C., Lim, T. W., Kim, N. H., Chung, W. and Kim, G. P., 1998, "Developing the Thermoplastic Water Pump and Power Steering Pulley for a Passenger Car," SAE Technical Paper 980736.
  10. Maggana, C. and Pissis, P., 1999, "Water sorption and diffusion studies in an epoxy resin system," Journal of Polymer Science Part B: Polymer Physics, Vol. 37, No. 11, pp. 1165-1182.<1165::AID-POLB11>3.0.CO;2-E
  11. Huang, H. and Talreja, R., 2006, "Numerical Simulation of Matrix Micro-cracking in Short Fiber Reinforced Polymer Composites: Initiation and Propagation," Composites Science and Technology, Vol. 66, No. 1, pp. 2743-2757.
  12. Tsenoglou, C. J., Pavlidou, S. and Papaspyrides, C. D., "Evaluation of Interfacial Relaxation due to Water Absorption in Fiber-Polymer Composites," Composites Science and Technology, Vol. 66, No. 1, pp. 2855-2864.