阶梯形超声变幅杆谐振频率的瑞利修正

Rayleigh Modification on Resonance Frequency of Stepped Ultrasonic Horn

在设计阶梯形超声变幅杆时,变幅杆的频率仿真值往往小于设计值;变幅杆的截面尺寸越大,这种偏差也越明显。按照瑞利修正理论,理论分析了这种现象产生的原因;在考虑变幅杆纵向振动后,给出谐振频率的瑞利修正值。重点推导了比较常用的粗细等长变幅杆的频率修正公式。借助有限元分析软件workbench对一组阶梯型变幅杆进行模态分析;获取不同半径变幅杆的谐振频率仿真值。分析比较理论值与仿真值;结果表明,按照瑞利修正理论修正后的频率值能更好地与仿真结果相吻合。这对于大截面阶梯形变幅杆的理论设计有一定指导意义。

In the design of stepped ultrasonic horns,the simulation values of amplitude frequency are often less than design values. The section sizes of the horns aregreater,and deviation of the results is more obvious. According to the Rayleigh modification theory,the cause of this phenomenon was analyzed theoretically. Considering the longitudinal vibration of horn,the revised resonance frequency was given.The correction formula of the amplitude frequency of the same length was deduced.With the help of finite element analysis software workbench,modal analysis of a set of horns was carried out. Simulation values of resonance frequency of different radius were obtained. The theoretical values and simulation values werecompared. The results showed that the revised frequency values according to the Rayleigh correction theory could coincide with the simulation results better. For design of the big cross section of stepped ultrasonic horn,it has certainsignificance.