DOI QR코드

DOI QR Code

VaRI 공정 유동해석 간소화 방법에 대한 연구

A Study on Simplifying Flow Analysis of VaRI Process

  • Kim, Yeongmin (Composites Research Division, Korea Institute of Materials Science) ;
  • Lee, Jungwan (Composites Research Division, Korea Institute of Materials Science) ;
  • Kim, Jungsoo (Composites Research Division, Korea Institute of Materials Science) ;
  • Ahn, Sehoon (Composites Research Division, Korea Institute of Materials Science) ;
  • Oh, Youngseok (Composites Research Division, Korea Institute of Materials Science) ;
  • Yi, Jin Woo (Composites Research Division, Korea Institute of Materials Science) ;
  • Kim, Wiedae (Department of Aerospace Engineering, Pusan National University) ;
  • Um, Moon-kwang (Composites Research Division, Korea Institute of Materials Science)
  • 투고 : 2021.07.21
  • 심사 : 2021.08.04
  • 발행 : 2021.09.03

초록

VaRI(Vacuum assisted Resin Infusion) 공정은 공정비용이 저렴하며, 크기가 큰 복합재 제작에 적합한 OoA(Out of Autoclave) 공정이다. VaRI 공정에서는 원할한 수지 주입을 위해 섬유 상단에 유로망을 적층한다. 수지는 이 유로망을 따라 섬유의 면 방향으로 빠르게 공급되고, 공급된 수지는 다시 섬유의 두께방향으로 함침된다. 면방향의 유동과 두께방향의 유동이 동시에 일어나기 때문에 수지의 유동을 예측하기 힘들며, 수지 주입과정을 예측하기 위해 3D 수치해석 프로그램이 사용되고 있다. 하지만, 3D로 해석하기 위해서 섬유와 유로망의 두께방향에 많은 Element가 필요하고, 이로 인해 제품의 크기가 클수록 해석시간이 오래 걸린다. 따라서 본 연구에서는 3D 유동해석을 2D 해석으로 간소화하여 유동해석에 소요되는 시간을 줄이는 방법을 제시하였다. 3D 유동해석과 간소화된 2D 유동해석을 동일조건에서 비교하여 효용성을 검증하였고, 충진시간 오차율은 약 7%, 유동해석시간 감소율은 약 95%로 나타났다. 또한 3D 해석에서 섬유 상, 중, 하단 간의 유동 전진 거리의 차이가 일정하다는 것을 활용하여 간소화된 2D 유동해석에서도 상, 중, 하단의 유동 전진 거리를 예측할 수 있었다.

VaRI(Vacuum assisted Resin Infusion) process, which is cost effective and suitable for manufacturing large-sized composites, is an OoA(Out-of Autoclave) process. For rapid resin infusion in the VaRI process, a DM(distribution media) is placed on top of the fabric. The resin is rapidly supplied in plane direction of the fiber along the DM, and then the supplied resin is impregnated in the out-of-plane direction of fiber. It is difficult to predict the flow of resin because the flow of in-plane direction and the out-of-plane direction occur together, and a 3D numerical analysis program is used to simulate the resin infusion process. However, in order to analyze in 3D, many elements are required in the out-of-plane direction of fabric. And the product size is larger, the longer the analysis time needs. Therefore, in this study, a method was suggested to reduce the time required for flow analysis by simplifying the 3D flow analysis to 2D flow analysis. The usefulness was verified by comparing the 3D flow analysis with the simplified 2D flow analysis at the same conditions. The filling time error was about 7% and the reduction of flow analysis time was about 95%. In addition, by utilizing the constant difference in the flow front between the top, middle, and bottom of the fabric of the 3D analysis, the flow front of the top, middle, and bottom of the fabric can be also predicted in the 2D flow analysis.

키워드

과제정보

본 연구는 산업통상자원부(No.20011022)의 지원을 받아 수행되었으며 이에 감사드립니다.

참고문헌

  1. Lee, J.H., Kim, W.H., Kim, Y.S., and Choi, S.W., "A Study on the Approach to Reduce in the Aviation GHG Emissions in Korea," Jounal of the Korean Society for Aviation and Aeronautics, Vol. 24, No. 1, 2016, pp. 47-54.
  2. Kim, K.S., and Park, S.J., "Technique Status of Carbon Fibers-reinforced Composites for Aircrafts," Elastomers and Composites, Vol. 46, No. 2, 2011, pp. 118-124.
  3. Harshe, R., "A Review on Advanced Out-of-Autoclave Composites Processing," Journal of the Indian Institute of Science, Vol. 95, No. 3, 2015, pp. 207-220.
  4. Chen, R., Dong, C., Liang, Z., Zhang, C., and Wang, B., "Flow Modeling and Simulation for Vacuum Assisted Resin Transfer Molding Process with the Equivalent Permeability Method," Polymer Composites, Vol. 25, No. 2, 2004, pp. 146-164. https://doi.org/10.1002/pc.20012
  5. Trochu, F., Gauvin, R., and Gao, D.M., "Numerical Analysis of the Resin Transfer Molding Process by the Finite Element Method," Advances in Polymer Technology: Journal of the Polymer Processing Institute, Vol. 12, No. 4, 1993, pp. 329-342. https://doi.org/10.1002/adv.1993.060120401
  6. Fuqua, M., and Glancey, J.L., "A Port Injection Process for Improved Resin Delivery and Flow Control in Vacuum-assisted Resin Transfer Molding," ASME International Mechanical Engineering Congress and Exposition, Vol. 4773, 2006, pp. 45-57.
  7. Jhan, Y.T., Lee, Y.J., and Chung, C.H., "Experimental and Numerical Investigation of the VARTM Process with a Sandwich Structure," Journal of composite materials, Vol. 46, No. 12, 2012, pp. 1417-1430. https://doi.org/10.1177/0021998311418703
  8. Park, Y.H., Kang, M.G., and Lee, W.I., "A Dual-Scale Analysis of Macroscopic Resin Flow in Vacuum Assisted Resin Transfer Molding Process," Journal of the Korean Society for Composite Materials, Vol. 15, No. 6, 2002, pp. 1-7.
  9. Dong, C., "An Equivalent Medium Method for the Vacuum Assisted Resin Transfer Molding Process Simulation," Journal of Comaterials, Vol. 40, No. 13, 2006, pp. 1193-1213.
  10. Chan, A.W., and Hwang, S.T., "Anisotropic In-plane Permeability of Fabric Media," Polymer Engineering & Science, Vol. 31, No. 16, pp. 1233-1239. https://doi.org/10.1002/pen.760311613