Influence of External Forces on the Detectability of the Resonance Frequency of Ultrasonic Vibration Systems

Performance of systems can be significantly enhanced by using ultrasonic vibrations. However, control of these processes under varying loads is difficult and requires constant regulation of the system’s operating frequency. Applying sensors to measure mechanical vibrations and using these to control the system might offer benefits compared to approaches based on electrical signals. In this work, an experimental stand is designed to examine the influence of external forces on the behavior of ultrasonic systems and the detectability of their resonance frequency based on mechanical and electrical signals under changing loads. Results show the differences between the resonance frequencies of the electrical and mechanical resonant circuit, the influence of external forces on the resonance frequency as well as the resulting maximum acceleration at the tip of the sonotrode. They also highlight the importance of a control system based on mechanical signals to better monitor the process.