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

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

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