铜锌合金的动态力学特征及本构关系  

Dynamic mechanical properties and constitutive relation of Cu-Zn alloy

作　　者：武国飞 肖强强[1] 黄正祥[1] 祖旭东[1] WU Guofei;XIAO Qiangqiang;HUANG Zhengxiang;ZU Xudong(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院,江苏南京210094

出　　处：《兵器材料科学与工程》2022年第2期58-65,共8页Ordnance Material Science and Engineering

基　　金：基础加强计划技术领域基金(2020-JCJQ-JJ-405)。

摘　　要：为准确可靠的拟合铜锌合金在高应变率下的本构模型,用霍普金森压杆(SHPB)装置和电子万能试验机分别对帽形、圆柱、拉伸试样进行动态冲击试验和准静态拉伸试验,得到不同应变率下的应力-应变曲线,进而得到JohnsonCook本构模型相关参数。结果表明:剪切应变率为6.3×10^(4)~7.8×10^(4)s^(-1)时,铜锌合金表现出明显的应变率强化效应及热软化效应;在真实压缩应变率为1400~2245 s^(-1)时,用线性拟合获得的应变率强化参数能反映铜锌合金的动态力学特性,但不能准确反映其在更高应变率下的动态力学性能;用Cowper-Symonds应变率强化效应系数修正公式得到符合较高应变率下的应变率强化参数,C_(1)、C_(2)分别为2.0×10^(-3)、0.71,修正后的Johnson-Cook本构模型计算结果与试验数据吻合度较高,说明可有效预测铜锌合金的动态力学性能。In order to accurately and reliably fit of the Cu-Zn alloy constitutive model under high strain rate,dynamic impact experiment and quasi static tensile were carried out on the hat shaped specimen,cylinder specimen and tensile specimen using split Hopkinson pressure bar(SHPB)experimental apparatus and electronic universal testing machine respectively,and the stress-strain curves of different strain rates were obtained,and then the Johnson-Cook constitutive model were obtained.The results show that Cu-Zn alloy exhibits obvious strain rate strengthening effect and heat softening effect as the shear strain rate is in the range of 6.3×10^(4)~7.8×10^(4)s^(-1).As the true compression strain rate is in the range of 1400-2245 s^(-1),the strain rate strengthening parameters obtained by linear fitting method can reflect the dynamic mechanical properties of Cu-Zn alloy,but can′t accurately reflect its dynamic mechanical properties at higher strain rates.The strain rate strengthening parameters with higher strain rates are obtained by Cowper-Symonds modified formula of strain rate strengthening effect coefficient.Cland C_(2) values are 2.0×10^(-3) and 0.71,respectively.And the calculated results of the modified Johnson-Cook constitutive model are in good agreement with experimental data,which shows that the dynamic mechanical properties of Cu-Zn alloy can be predicted effectively.

关 键 词：动态力学性能 不同应变率 绝热温升 单轴压缩 本构模型 

分 类 号：TG146.11[一般工业技术—材料科学与工程]