大负载纵弯谐振变幅器谐振特性的研究与试验

Research and Experiment of Resonance Characteristics of Longitudinal Flexural Resonant Transducer with Large Load

大负载功率超声纵弯谐振变幅器在旋转超声加工、超声清洗、金属疲劳检测等领域应用广泛,针对大负载工具的应用现状,对阶梯环盘负载与变幅杆组成的功率超声纵弯谐振变幅器进行了设计研究。基于Mindlin中厚板理论,建立了纵弯谐振变幅器的振动模型,推导了频率方程与变幅器振型解析表达式,设计了不同材料大负载功率超声纵弯谐振变幅器。通过阻抗分析试验和超声谐振试验对所设计的变幅器进行了谐振特性研究。对比试验结果证明:大负载功率超声纵弯谐振变幅器的谐振频率与设计频率相比最大误差为4.95%,理论计算与谐振试验得到的三环盘振幅曲线的整体形态一致,零振幅位置最大偏差为6.51%,变幅器作纵弯谐振,为超声谐振系统的设计与应用提供了技术参考。

Ultrasonic longitudinal-flexural resonant transducer with large load is widely applied in the fields of rotary ultrasonic machining,ultrasonic cleaning,metal fatigue detection and so on. According to the application status of tools with large load,ultrasonic longitudinal-flexural resonant transducers consisted of horns and stepped annular plates were designed and researched. Based on the Mindlin theory,a vibration model of longitudinal-flexural resonant transducer was established.Frequency equation and analytic expression of amplitude of transducer were derived. Ultrasonic longitudinal-flexural resonant transducers with multi materials with large load were designed. The resonant characteristics of the transducers were researched by impedance analysis experiment and ultrasonic resonance experiment. The results of contrast experiments showed that the maximum error of resonant frequency and design frequency of ultrasonic longitudinal-flexural resonant transducers with large load was 4.95%. The overall shape of amplitude curves of 3-annular plate obtained by theoretical calculation and resonance experiment was consistent. The maximum deviation of amplitude position of zero was 6.51%. Transducers were in the state of longitudinal-flexural resonant. It provided a technical reference for the design and application of ultrasonic resonance system.