高导无氧铜的临界冲击拉伸速度

Critical impact velocity for oxygen-free high-conductivity copper in tension

基于气炮系统,提出了一种新的临界冲击拉伸速度实验方法。实验装置主要由2部分组成:气体炮系统驱动弹丸和弹丸击靶牵引多根拉伸杆试件。采用该实验方法对高导无氧铜进行了临界冲击拉伸速度实验。对于一维应力的临界冲击拉伸速度实验,探讨了一种完全热耦合的在颈缩区域计及塑性约束系数以及空穴增长与聚集效应的数值模拟方法。高导无氧铜的临界冲击拉伸速度实验的数值模拟结果表明,采用Zerilli-Armstrong本构关系预估的实验临界冲击拉伸速度比采用Johnson-Cook本构关系预估的更符合实验。

A novel facility for tensile testing at the critical impact velocity was designed in a gas gun system. This facility consists of two assemblies, firstly, a gas gun system to propel the projectile and secondly, the tension mechanism to grip and strain the specimen bars. The critical impact velocity experiments in tension of oxygen-free high-conductivity copper were carried out using the novel facility. A numerical simulation was presented for uniaxial tensile testing at the critical impact velocity in complete thermal coupling. In case of necking, the plastic constraint factor, the void growth and coalescence were considered. The computed results with the Johnson-Cook or Zerilli-Armstrong constitutive relations, respectively, show that the Zerilli-Armstrong constitutive relation give a better prediction of the experimental critical impact velocity in tension for oxygen-free high-conductivity copper.