DOI QR코드

DOI QR Code

동일 충격 에너지 조건하에서 다공질 고분자의 충격거동에 관한 연구

Crashworthy behaviour of cellular polymer under constant impact energy

  • 정광영 (국립공주대학교 공과대학 기계자동차공학부) ;
  • 전성식 (국립공주대학교 공과대학 기계자동차공학부)
  • 발행 : 2009.08.31

초록

본 연구에서는 충돌속도가 다르지만, 총 충돌에너지는 동일하게 유지한 상태에서 충돌을 가했을 때 발포 고분자의 응력-변형률 관계와 충돌에너지 흡수 특성에 관하여 고찰하였다. 이는 충돌시 관성과 변형률 속도에 변화를 주어 재료의 반응거동 및 특성을 파악하기 위함이다. 두가지 다른 밀도(64 $kg/m^3$, 89 $kg/m^3$)를 갖는 발포고분자시편에 대한 준정적시험과 충돌시험이 수행되었다. 또한 Sherwood-Frost 모델과 임펄스 모멘텀 이론의 두가지가 연성된 방정식을이용하여 발포고분자의 구성방정식으로 제안하였다.\ 제안된 구성방정식을 이용하여, 응력변형률 선도를 구하고, 충돌시험결과와 비교하여, 본 구성방정식이 우수하게 결과를 예측할 수 있는 것으로 나타났다.

Characterisation of the stress-strain relationship as well as crashworthiness of cellular polymer was investigated under constant impact energy with different velocities, considering inertia and strain rate effects simultaneously during the impact testing. Quasi-static and impact tests were carried out for two different density (64 $kg/m^3$, 89 $kg/m^3$) cellular polymer specimens. Also, the equations, coupled with the Sherwood-Frost model and the Impulse-Momentum theory, were employed to build the constitutive relation of the cellular polymer. The nominal stress-strain curves obtained from the constitutive relation were compared with results from impact tests and showed to be in good agreement.

키워드

참고문헌

  1. Szycher, M., Szycher's Handbook of Polyurethanes Boca Raton: CRC press, 1999
  2. Shim, V.P.W., Tu, Z.H. and Lim, C.T., "Two-dimensional Response of Crushable Polyurethane Foam to Low Velocity Impact," lnt. J. lmpact Eng., Vol. 24, 2000, pp. 703-731 https://doi.org/10.1016/S0734-743X(99)00149-9
  3. Meguid, S.A., Cheon, S.S. and EI-Abbasi, N., "FE Modelling of Deformation Localization in Metallic Foams," Finite Elements in Analysis and Design, Vol.38, 2002, pp.631-643 https://doi.org/10.1016/S0168-874X(01)00096-8
  4. Kim, A., Hasan, M.D.A., Cheon, S.S. and Lee, H.J., "The Constitutive Behavior of Metallic Foams using Nanoindentation Technique and FE ModeJIing," Key Engineering Materials, Vol. 297-300, 2005, pp.1050-1055 https://doi.org/10.4028/www.scientific.net/KEM.297-300.1050
  5. Kim, A, Tunvir, K., Jeong, G.D. and Cheon, S.S., "A Multi-cell FE-model for Compressive Behaviour Analysis of Heterogeneous AI-alloy Foam," Modelling and Simulation in Materials Science and Engineering, Vol. 14, 2006, pp.933-945 https://doi.org/10.1088/0965-0393/14/6/004
  6. Avalle, M., Belingardi, G. and Montanini, R., "Characterization of Polymeric Structural Foams under Compressive Impact Loading by Means of Energy Absorption Diagram," lnt J. lmpact Eng. , Vol. 25, 2001 , pp.455-472 https://doi.org/10.1016/S0734-743X(00)00060-9
  7. Rusch, K.C. "Load-compression Behaviour of Flexible Foams," J. Applied Polymer Science, Vol.13, 1969, pp. 2297-2311 https://doi.org/10.1002/app.1969.070131106
  8. Meinecke, E.A. and Schwaber, D.M., "Energy Absorption in Polymeric Foams," J. Applied Polymer Science, Vol. 14, 1970, pp. 2239-2248 https://doi.org/10.1002/app.1970.070140905
  9. Sherwood, J.A. and Frost, C.C., "Constitutive Modeling and Simulation of Energy Absorbing Polyurethane Foam Under Impact Loading," Polymer Engineering and Science, Vol. 32, 1992, pp. 1138-1146 https://doi.org/10.1002/pen.760321611
  10. Su, X.Y., Yu, T.X. and Reid, S.R., "Inertia-sensitive lmpact Energy-absorbing Structures Part 1: Effects of Inertia and Elasticity," Int. J. Impact Eng. , Vol. 16, 1995, pp. 651-672 https://doi.org/10.1016/0734-743X(94)00061-Z
  11. Su, X.Y., Yu, T.X. and Reid, S.R., "Inertia-sensitive Impact Energy-absorbing Structures Part II: Effect of Strain-rate," Int. J. Impact Eng., Vol. 16, 1995, pp. 673-689 https://doi.org/10.1016/0734-743X(94)00062-2
  12. Tam, L.L. and Calladine, C.R , "lnertia and Strain-rate Effects in a Simple Plate-structure Under Impact Loading," Int J. Impact Eng., Vol. 11, 1991, pp. 349-377 https://doi.org/10.1016/0734-743X(91)90044-G
  13. Langseth, M. Hopperstad, O.S. and Berstad, T., "Crashworthiness of Aluminium Extrusions: Validation of Numerical Simulation, Effects of Mass Ratio and Impact Velocity," Int. J. Impact Eng., Vol. 22, 1999, pp. 829-854 https://doi.org/10.1016/S0734-743X(98)00070-0
  14. Beer, F.P. and Johnston Jr., E.R., Vector Mechanics for Engineers: Dynamics, McGraw-Hill, 1981
  15. Gibson, L.J. and Ashby, M.F., Cellular Solids: Structure and Properties, Pergamon Press, 1998
  16. Paul, A. and Ramamurty, U., "Strain Rate Sensitivity of a Closed-cell Aluminium Foam," Materials Science and Engineering A, Vol. 281 , 2000, pp. 1-7 https://doi.org/10.1016/S0921-5093(99)00750-9
  17. Lopatnikov, S.L., Gama, B.A. and Gillespie Jr J. W., "Modeling the Progressive Collapse Behaviour of Metal Foams," Int. J. Impact Eng., Vol. 34, 2007, pp. 587-595 https://doi.org/10.1016/j.ijimpeng.2005.12.004
  18. 전성식, "통계적 유한요소모텔을 이용한 발포된 금속기지 복합재료의 인장특성," 한국복합재료학회지, 제17권, 2004, pp. 34-39