弹性模量对TC4超声刀变幅杆性能影响的模拟

Simulation of the influence of elastic modulus on the performance of TC4 ultrasonic amplitude transformer horn

变幅杆是超声刀的重要组成部分,起放大振幅的作用。材料弹性模量的改变对同一结构下变幅杆的性能会产生影响。利用纵向波动方程理论进行超声变幅杆的参数化建模,并使用有限元模拟软件对不同弹性模量变幅杆进行模态与谐响应分析。在满足变幅杆设计要求的前提下,研究了TC4钛合金弹性模量对阶梯悬链形超声刀变幅杆结构共振频率、输出端位移幅值和应力极大值的影响。研究结果表明:结构共振频率随TC4弹性模量的增加而升高;输出端位移幅值和应力极大值均随TC4钛合金弹性模量增加先增大后减小;工作频率为55.5 kHz,弹性模量在106~107 GPa,110~111 GPa时变幅杆的应力极大值均小于400 MPa,输出端位移幅值均在30~50μm,达到超声刀变幅杆的性能要求。

The horn is an important part of the ultrasonic scalpel,which plays a role in amplifying the amplitude.The change of the elastic modulus of the material will affect the performance of the horn under the same structure.A finite element simulation software was being used to analysis the modal and harmonic with different elastic modulus response of the TC4 titanium alloy step catenary ultrasonic scalpel transformer horn in the present work,based on the modal created by using the longitudinal wave equation theory.With the premise that the design requirements of the horn was satisfied,the effect of elastic modulus on the resonant frequency,displacement amplitude of the output end and maximum stress of the transformer horn was investigated.The results show that the resonant frequency increases with the increase of the elastic modulus.The displacement amplitude of the output end and the maximum stress firstly increase and then decrease with the increasing elastic modulus.The simulated maximum stress is less than 400 MPa,with the elastic modulus of 106~107 GPa and 110~111 GPa and working frequency of 55.5 kHz.And the corresponding displacement amplitude of the output end is 30~50μm.The maximum stress and displacement amplitude meet the performance requirements of the ultrasonic scalpel transformer horn.