超声变幅杆振动温升及其对振动稳定性的影响

Vibration Heating of Ultrasonic Horn and Its Influence on Vibration Stability

在变幅杆振动中,变幅杆的自身阻尼特性以及与螺栓/工具头的耦合会导致明显温升.为研究该温升特性并探讨其对变幅杆振动稳定性的影响,采用数值模拟得到了纵振变幅杆的总功耗密度和温度分布;通过红外热成像测试对变幅杆理论温升进行了验证,并分析了不同材料的螺栓与工具头连接对温升的影响.结合数值模态分析与实验分析,进一步探讨了温升对变幅杆谐振频率与振幅的影响规律.结果表明,变幅杆连续运行时温升趋于平衡,该平衡点取决于螺栓材料、变幅杆材料和环境因素.对于低阻尼TC4钛合金变幅杆,螺栓处能量损耗为主要热源,其中45钢螺栓发热量占97.7%,而采用TC4钛合金螺栓和TU2紫铜工具头可显著减小温升.同时发现,变幅杆谐振频率与温升成线性负相关,振幅因温升有所降低,二者均稳定在平衡温度点.

In the vibration of the horn,the damping characteristics of the ultrasonic horn and its coupling with the bolt/tool head will lead to obvious temperature rise.In order to analyze the temperature rise characteristic and explore its influence on the vibration stability of the ultrasonic horn,the total power density and temperature distribution of the longitudinal vibration horn were obtained by numerical simulation.The theoretical temperature rise of the ultrasonic horn was verified by infrared thermal imaging test,and the influence of bolts and tool heads of different materials on the temperature rise was analyzed.Combining the numerical modal analysis and experimental analysis,the influence of temperature rise on the resonant frequency and amplitude of the horn was further discussed.The results show that the temperature rise tends to be balanced during continuous operation of the ultrasonic horn,and the equilibrium point depends on the bolt material,horn material and environmental factors.For low damping TC4 horns,energy loss at bolt is the main heat source,of which 45 steel bolts generate 97.7%of the heat,while TC4 bolts and tool heads can significantly reduce the temperature rise.At the same time,it is found that the resonance frequency of the ultrasonic horn is linearly negatively correlated with the temperature rise.The amplitude is reduced due to the temperature rise,and both of them are stable at the equilibrium temperature point.