子弹冲击下TiNi固支梁的结构动态响应特性研究

采用改装的霍普金森压杆装置结合数值模拟对伪弹性TiNi合金固支梁的结构动态响应特性进行了研究。结果表明,在子弹冲击下,撞击点和固定端附近首先发生相变,并随着载荷增加,进一步产生相变铰,梁演变为二杆铰接机构。由于轴力作用,此处相变铰为拉伸侧的单边铰。与传统塑性铰不同,卸载后相变铰完全消失,梁回复原状没有残余变形。此外,对固支边界条件的实现及其对实验结果的影响进行了专门研究。

Investigation on Structural Dynamic Response of a Tini End Clamped Beam under Transversal Impact

Experimental investigation on structural dynamic response characteristic of a TiNi end clamped beam in Pseudo-elastic state was conducted by using modified Split Hopkinson Pressure Bar (SHPB) apparatus and a high-speed CCD camera combined with numerical simulation. Results reveal that under the projectile impact, the martensitic phase transition at both impacted position and fixed ends is observed in recorded strain signals. With the load increasing, phase transformation hinges (THs) is formed, which causes beam turn into a hinged bar structure. Here, the THs are single side hinges due to the effect of axial force. Differing from conventional plastic hinges, the THs disappear and the TiNi specimen recovers its original shape after unloading without any residual deformation due to reverse phase transition. In addition, the realization and the effect of fixed boundary condition on experimental results were also technically discussed.