Dynamic Constitutive Equations of Auto-body Steel Sheets with the Variation of Temperature (II) - Flow Stress Constitutive Equation -

차체용 강판의 온도에 따른 동적 구성방정식에 관한 연구 (II) - 온도에 따른 동적 구성방정식 -

  • 이희종 (한국과학기술원 기계공학과) ;
  • 송정한 (한국과학기술원 기계공학과) ;
  • 박성호 (포스코 자동차강재연구센터) ;
  • 허훈 (한국과학기술원 기계공학과)
  • Published : 2007.02.01


This paper is concerned with the empirical flow stress constitutive equation of steel sheets for an auto-body with the variation of temperature and strain rate. In order to represent the strain rate and temperature dependent behavior of the flow stress at the intermediate strain rates accurately, an empirical hardening equation is suggested by modifying the well-known Khan-Huang-Liang model. The temperature and strain rate dependent sensitivity of the flow stress at the intermediate strain rate is considered in the hardening equation by coupling the strain, the strain rate and the temperature. The hardening equation suggested gives good correlation with experimental results at various intermediate strain rates and temperatures. In order to verify the effectiveness and accuracy of the suggested model quantitatively, the standard deviation of the fitted result from the experimental one is compared with those of the other two well-known empirical constitutive models such as the Johnson-Cook and the Khan-Huang-Liang models. The comparison demonstrates that the suggested model gives relatively well description of experimental results at various strain rates and temperatures.


Intermediate Strain Rate;Strain Rate Sensitivity;Temperature Sensitivity;Constitutive Equation


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