한국자동차공학회논문집 (Transactions of the Korean Society of Automotive Engineers)

  • 제18권2호
  • /
  • Pages.56-60
  • /
  • 2010
  • /
  • 1225-6382(pISSN)
  • /
  • 2234-0149(eISSN)
한국자동차공학회 (The Korean Society of Automotive Engineers)
권호 표지

Hill48 이차 항복식을 이용한 변형률 속도에 따른 수정된 항복곡면의 구성

Construction of Modified Yield Loci with Respect to the Strain Rates using Hill48 Quadratic Yield Function

  • 이창수 (한국과학기술원 기계항공시스템학부) ;
  • 배기현 (한국과학기술원 기계항공시스템학부) ;
  • 김석봉 (한국과학기술원 기계항공시스템학부) ;
  • 허훈 (한국과학기술원 기계항공시스템학부)
  • Lee, Chang-Soo (School of Mechanical, Aerospace & Systems Engineering, KAIST) ;
  • Bae, Gi-Hyun (School of Mechanical, Aerospace & Systems Engineering, KAIST) ;
  • Kim, Seok-Bong (School of Mechanical, Aerospace & Systems Engineering, KAIST) ;
  • Huh, Hoon (School of Mechanical, Aerospace & Systems Engineering, KAIST)
  • 투고 : 2009.06.12
  • 심사 : 2009.09.10
  • 발행 : 2010.03.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

Since the forming process involves the strain rate effect, a yield function considering the strain rate is indispensible to predict the accurate final blank shape in the forming simulation. One of the most widely used in the forming analysis is the Hill48 quadratic yield function due to its simplicity and low computing cost. In this paper, static and dynamic uni-axial tensile tests according to the loading direction have been carried out in order to measure the yield stress and the r-value. Based on the measured results, the Hill48 yield loci have been constructed, and their performance to describe the plastic anisotropy has been quantitatively evaluated. The Hill48 quadratic yield function has been modified using convex combination in order to achieve accurate approximation of anisotropy at the rolling and transverse direction.

키워드

참고문헌

  1. R. Hill, "A Theory of a Yielding and Plastic Flow of a Anisotropic Metals," Proc. Roy. Soc., A193, pp.281-297, 1948.
  2. F. Barlat, J. C. Brem, J. W. Yoon, K. Chung, R. E. Dick, D. J. Lege, F. Pourboghrat, S.-H. Choi and E. Chu, "Plane Stress Yield Function for Aluminum Alloy Sheets-Part 1: Theory," Int. J. Plasticity, Vol.19, pp.1297-1319, 2003. https://doi.org/10.1016/S0749-6419(02)00019-0
  3. H. Huh, J. H. Lim and S. H. Park, "High Speed Tensile Test of Steel Sheets for the Stress-strain Curve at the Intermediate Strain Rate," Int. J. Automotive Technology, Vol.10, No.2, pp.195- 204, 2009. https://doi.org/10.1007/s12239-009-0023-3
  4. H. Huh, S. B. Kim, J. H. Song and J. H. Lim, "Dynamic Tensile Characteristics of TRIP-type and DP-type Steel Sheets for an Auto-body," Int. J. Mech. Sci., Vol.50, pp.918-931, 2008. https://doi.org/10.1016/j.ijmecsci.2007.09.004
  5. R. Hill, "The Mathematical Theory of Plasticity," Clarendon Press, Oxford, p.138, 1950.
  6. M. G. Lee, D. Kim, C. Kim, M. L. Wenner, H. R. Wagoner and K. Chung, "Spring-back Evaluation of Automotive Sheets based on Isotropic-kinematic Hardening Laws and Non-quadratic Anisotropic Yield Functions: Part II: Characterization of Material Properties," Int. J. Plasticity, Vol.21, Issue.5, pp.883-914, 2005.
  7. A. D. Belegundu and T. R. Chandrupatla, Optimization Concepts and Applications in Engineering, Simon & Schuster / A Viacom Company, Prentice-Hall, p.61, 1999.