薄壁管拉扭复合相变波的实验研究

An experimental study on the stress waves with phase transition under combined tension-torsion loading

为了观察相变波在复合应力加载条件下的传播特性,通过一套薄壁管预扭冲击拉伸的实验装置,对相变材料NiTi合金薄壁管进行了预扭冲击拉伸的实验研究。实验观察到明显的拉扭耦合快波结构,证明了复合应力下相变波确实具有耦合特性,此外,实验结果还表明相变材料NiTi合金在拉扭复合应力下的相变临界点具有明显的率无关性。由于拉扭耦合慢波部分的应变变化较小,在实验波形中不易分辨,对实验过程进行了数值模拟,模拟结果和实验基本吻合,并能观察到相应的耦合慢波部分。

In order to investigate the propagation of stress waves with phase transition under combined stress loading conditions,impact tension loading was applied on a pre-torqued thin walled tube made of NiTi alloy,which transformed its phase under stress loading. The coupling fast waves were observed,proving that the stress waves with phase transition under combined loading were coupling. The results show that the critical criterion for phase transition under combined stress is rate-nonsensitive. The signal of coupling slow waves was very small. A simulation was performed,which fit well with the experiment. The coupling slow waves could be distinguished.