Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
권호 표지

High Speed Tensile Tests of Steel Sheets for an Auto-body at the Intermediate Strain Rate

중변형률 속도에서의 차체용 강판의 고속 인장실험

  • Lim, Ji-Ho (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology) ;
  • Kim, Seok-Bong (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology) ;
  • Kim, Jin-Sung (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology) ;
  • Huh, Hoon (Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology) ;
  • Lim, Jong-Dae (Hyundai Motor Company) ;
  • Park, Sung-Ho (POSCO)
  • Published : 2005.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

This paper introduces a newly developed high speed material testing apparatus for tensile tests at the strain rate up to 500/sec. The tensile properties of sheet metals are indispensable for the accurate crashworthiness analysis of auto-bodies since the local strain rate reaches to 500/sec in the car crash. An appropriate experimental method has to be developed to acquire the tensile properties at the intermediate strain rate ranged from 0.003/sec to 200/sec. Tensile tests of various different steel sheets for an auto-body were perform ed to obtain the dynamic properties with respect to the strain rate. The dimensions of specimens that can provide the reasonable results were determined by the finite element analysis. A special jig fixture of a load cell is designed to reduce the load ringing phenomenon induced by unstable stress propagation at the high strain rate. Stress-strain curves were acquired for each steel sheet from the dynamic tensile test and utilized to obtain the relationship of the stress to the strain rate.

Keywords

References

  1. H. Huh, J. H. Lim, J. H. Song, K. S. Lee, Y. W. Lee and S. S. Han, 'Crash worth ness Assessment of Side Impact of an Auto-Body with 60TRIP Steel for Side Members,' Int. J. Automotive Technology, Vol.4, No.3, pp.149-156, 2003
  2. H. Kolsky, Stress Waves in Solids, Dover, New York, pp.41-98, 1963
  3. U. S. Lindholm and L. M. Yeakley, 'High Strain-rate Testing: Tension and Compression,' Experimental Mechanics, Vol.8, pp.1-9, 1968 https://doi.org/10.1007/BF02326244
  4. J. Duffy, J. D. Campbell and R. H. Hawley, 'On the Use of a Torsional Split Hopkinson Bar to Study Rate Effect in 1100-0 Aluminum,' J. Appl. Mech. Trans. ASME, Vol.38, pp.83-91, 1971 https://doi.org/10.1115/1.3408771
  5. G. H. Staab and A. Gilat, 'A Direct-tension Split Hopkinson Bar for High Strain-rate Testing,' Experimental Mechanics, Vol.31, pp.232-235, 1988
  6. H. Huh, W. J. Kang and S. S. Han, 'A Tension Split Hopkinson bar for Investigating the Dynamic Behavior of Sheet Metals,' Experimental Mechanics, Vol.42, pp.8-17, 2002 https://doi.org/10.1007/BF02411046
  7. G. B. Dudder, 'Drop Tower Compression Test,' Metals Handbook, 9th Ed., American Society for Metals, pp.196-199, 1985
  8. D. R. Ambur, C. B. Prasad and W .A. Waters Jr. 'A Dropped-weight Apparatus for Low-speed Impact Tesing of Composite Structures,' Experimental Mechanics, Vol.3, pp.77-82, 1995
  9. M. A. M eyers, Dynamic Behavior of materials, John Wiley & Sons, New York, 1994
  10. 'Mechanical Testing,' ASM Handbook, ASM Intl., Metals Park, Ohio, Vol.8, 1985
  11. K. Miura, S. Takagi, T. Obara and S. Tanimura, 'High Strain Rate Deformation of High Strength Sheet Steels for Automotive Parts,' SAE, 980952, 1998
  12. J. H. Lim, S. B. Kim, J. S. Kim, H. Huh, S. Y. Kwon, C. S. Yoon and S. H. Park, 'Study on the Fracture Elongation of the Steel Sheet at the Intermediate Strain Rate,' 2004 KSAE Spring Conference Proceedings, pp.1669-1974, 2004
  13. Instron Corporation, 'Operating Instructions of Instron Fast Track 8800 and Materials Test Control Systems,' 2002
  14. J. H. Lim and H. Huh, 'Dynamic Material Tests of Steel Sheets for an Auto-body Using the High Speed Material Testing Machine,' 2003 KSAE Fall Conference Proceedings, pp.1525-1530, 2003