高导无氧铜的高压与高应变率本构模型研究

On constitutive models of oxygen-free high-conductivity copper at high pressure and high strain rates

基于Y/G及G/B为常数的假设,构建了高导无氧铜的七种高压与高应变率本构模型.对于高导无氧铜进行了平面冲击波试验,采用纵向与横向锰铜应力计记录了试件中的纵向与横向应力,从而得到了屈服应力历史.用所构建的七种本构模型进行了数值模拟,并与高导无氧铜的平面冲击波试验结果进行比较.结果表明,平面冲击波载荷下高导无氧铜的屈服强度对于压力、密度、温度以及塑性应变的依赖性是本构描述的关键.而由Hopkinson试验取得的高导无氧铜高应变率本构模型,并不适合描述平面冲击波载荷下的本构特性.

In this paper,seven constitutive models for oxygen-free high conductivity copper at high pressure and high strain rate are constructed based on Y/G=constant and on G/B=constant,respectively（Y denoting the yield strength,G the shear modulus,B the bulk modulus）.The variations of longitudinal stress,transverse stress and yield strength of oxygen-free high conductivity copper with time under planar shock loading are obtained using the manganin stress gauge and compared with the predicted values by the constructed seven constitutive models.It is indicated that the pressure,density,temperature and plastic strain dependence of the yield strength for oxygen-free high conductivity copper under planar shock loading is essential to the constitutive description.It seems that the strength models of oxygen-free high conductivity copper obtained from SHPB tests and torsion tests are unavailing to the planar shock loading.