超声局部共振系统设计与试验研究

超声振动加工能明显降低切削力及切削热、减小刀具磨损、提高加工效率，广泛应用于加工硬、脆等难加工材料。为避免刀具负载对谐振频率的影响，利用局部共振理论将振动系统分为变幅杆和工具杆两个子系统分别进行设计。由子系统连接处的输入总阻抗为0进而推导了复杂声学系统的频率方程，计算出振动系统尺寸。计算结果表明：模态分析及实际测量结果与理论偏差小于3%，满足设计要求，验证了局部共振理论设计的合理性；采用该方法设计的声学系统不受刀具本身负载影响，且在加工时力的波动较小，在一定程度上提高了系统稳定性，表明局部共振系统具有良好的加工效果。

Design and Experimental Study of Ultrasonic Local Resonance System

In ultrasonic vibration machining, the cutting force and cutting heat are significantly reduced, the tool wear is reduced, and the machining efficiency is improved. The ultrasonic vibration machining process is widely used for machining the difficult-to-machine materials, such as hard and brittle materials. In order to avoid the influence of tool load on the resonant frequency, the local resonance theory is used to divide the vibration system into two subsystems. The frequency equation of complex acoustic system is derived from the total input impedance equal to zero at the junction of the subsystems, and the size of vibration system is calculated. Calculated results show that the modal analysis results and the actual measured results are less than 3% deviation from the theoretical values, which meets the design requirements and verifies the correctness of the theoretical design of local resonance. The acoustic system designed by this method is not affected by the tool load, the fluctuation of force during processing is small, and the stability of the system is improved to some extent, indicating that the local resonance system has a good processing effect.