采用有限元方法对超声波在缓冲杆中的传播结果进行了仿真，找出尾随信号产生的原因，通过打乱圆柱/空气界面的方法，设计出多种形状的超声缓冲杆。实验发现，具有单锥形和双锥形结构的钢制缓冲杆能够很好的抑制尾随信号的出现，同时随着双锥形缓冲杆锥角在一定范围内不断增大，抑制效果愈加明显，可以达到较高的信噪比。

Simulations of ultrasonic in the buffer rods using the finite element methods was presented firstly. It showed the reasons of the trailing signals and designed some kinds of buffer rods with different diameters by disturbing the cylinder/air boundary. Based on the data from the experiments, it was found that Aluminum buffer rods with a tapered shape and a double-tapered shape could well constrain the trailing signals. At the same time, the effect of the constraining became better and better with the rising of the angel of the double-tapered shape buffer rods in some ranges, thus leading to a high SNR.