A modified Johnson–Cook model for 7N01 aluminum alloy under dynamic condition  

作　　者：ZHANG Yi-ben YAO Song HONG Xiang WANG Zhong-gang 张一犇;姚松;洪翔;王中钢

机构地区：[1]Key Laboratory of Traffic Safety on Track of Ministry of Education,School of Traffic and Transportation Engineering,Central South University,Changsha 410075,China

出　　处：《Journal of Central South University》2017年第11期2550-2555,共6页中南大学学报（英文版）

基　　金：Projects(51275532,U1334208)supported by the National Natural Science Foundation of China;Project(2015BAG13B01)supported by National Science and Technology Support Program,China;Project(2016YFB1200602-33)supported by the National Key R&D Program of China;Project(NCET-12-0549)supported by the New Century Excellent Talents in University,China;Project(CSUZC201527)supported by the Open-Fund for the Valuable and Precision Instruments of Central South University,China

摘　　要：Tensile tests at different strain rates(0.0002, 0.002, 0.02, 1000 and 3000 s^(-1)) were carried out for 7N01 aluminum alloy. Low strain rate experiments(0.0002, 0.002 and 0.02 s^(-1)) were conducted using an electronic mechanical universal testing machine, while high strain rate experiments(1000, 3000 s^(-1)) were carried out through a split Hopkinson tensile bar. The experimental results showed that 7N01 aluminum alloy is strain rate sensitive. By introducing a correction scheme of the strain rate hardening coefficient, a modified Johnson–Cook model was proposed to describe the flow behaviors of 7N01 aluminum alloy. The proposed model fitted the experimental data better than the original Johnson–Cook model in plastic flow under dynamic condition. Numerical simulations of the dynamic tensile tests were performed using ABAQUS with the modified Johnson–Cook model. Digital image correlation was used together with high-speed photography to study the mechanical characters of specimen at high strain rate. Good correlations between the experiments results, numerical predictions and DIC results are achieved. High accuracy of the modified Johnson-Cook model was validated.Tensile tests at different strain rates(0.0002, 0.002, 0.02, 1000 and 3000 s^(-1)) were carried out for 7N01 aluminum alloy. Low strain rate experiments(0.0002, 0.002 and 0.02 s^(-1)) were conducted using an electronic mechanical universal testing machine, while high strain rate experiments(1000, 3000 s^(-1)) were carried out through a split Hopkinson tensile bar. The experimental results showed that 7N01 aluminum alloy is strain rate sensitive. By introducing a correction scheme of the strain rate hardening coefficient, a modified Johnson–Cook model was proposed to describe the flow behaviors of 7N01 aluminum alloy. The proposed model fitted the experimental data better than the original Johnson–Cook model in plastic flow under dynamic condition. Numerical simulations of the dynamic tensile tests were performed using ABAQUS with the modified Johnson–Cook model. Digital image correlation was used together with high-speed photography to study the mechanical characters of specimen at high strain rate. Good correlations between the experiments results, numerical predictions and DIC results are achieved. High accuracy of the modified Johnson-Cook model was validated.

关 键 词：aluminum alloy CONSTITUTIVE RELATION MODIFIED Johnson–Cook MODEL high strain rate digital image correlation FINITE element analysis 

分 类 号：TG146.21[一般工业技术—材料科学与工程]