Deformation behavior and constitutive model of DP780 high strength steel at high strain rates [DP780高强钢板材高应变率变形行为及本构模型]

作者：Liu D.-H.; Meng W.-J.^*; Meng J.-P.

来源：Journal of Plasticity Engineering, 2018, 25(1): 161-166 and 174.

DOI：10.3969/j.issn.1007-2012.2018.01.024

• Constitutive model
• DP780 high strength steel
• Dynamic tensile
• High strain rate

The MTS quasi-static and split Hopkinson bar dynamic tensile tests at strain rates 0.001,1150,1900,2800 and 4200 s -1 were carried out to study the constitutive behavior of DP780 high strength steel,the law of high strain rate deformation was obtained, and the Johnson-Cook (JC) dynamic constitutive model was proposed and modified subsequently. The results show that the deformation behavior of DP780 sheets under dynamic tension is of great difference from that of the quasi-static tensile process, exhibiting a significant strain rate strengthening effect. The yield and ultimate tensile strength of DP780 under dynamic tension condition are obviously higher than that under quasi-static condition, and the strengths increase with the increasing strain rates. However, the tendency of increasing disappears when the strain rate increases to 2800 s -1 because of the adiabatic heating effect. The modified JC model established based on dynamic tension data can describe and predict the tensile curves well.

• 单位
  南昌航空大学