TiNi合金圆薄板的横向冲击特性实验

Experimental study on dynamic behavior of thin circular plate of TiNi alloy subjected to transversal impact

利用改装的霍普金森压杆装置对周边固支伪弹性TiNi合金圆薄板进行了冲击实验,初步得到了该结构在时空2个尺度上的动态力学响应的演变发展现象和规律,包括板中弯曲波的传播、相变区的演化和全场的离面位移等,并和A3钢做了对比。结果表明,由于圆板的二维扩散效应,冲击过程中仅在TiNi板中心很小区域(约5mm)内形成相变区和相变铰,卸载后相变铰消失,钢试件则留下明显的残余变形。TiNi合金圆板的冲击特性受热弹性马氏体相变和逆相变的支配,不同于传统的弹塑性机制。

The experimental investigation of thin circular plate of pseudo-elastic TiNi alloy under fixed supports and transversal impact loading was conducted using a revised apparatus of Hopkinson bar.The experimental result of pseudo-elastic TiNi alloy was compared with that of A3 steel.The nature of dynamic mechanical response of the structure in spatio-temporal scale,including the propagation of flexural wave in the plate,evolution of transformation zones and full-field out-of-plane displacement were derived.The results show that transformation zones and transformation hinge may generate near the center of the plate （about 5 mm） because of two-dimensional diffusion effect of the circular plate under impact loading.After unloading,the transformation hinge disappeared,and obvious residual deformation was observed in the A3 steel plate.The impact response of thin circular plate of TiNi alloy is controlled by the thermo-elastic martensite phase transformation and inverse transformation,which differs from the conventional elastic-plastic mechanism.