Derivation of characteristic vibroacoustic parameters in Ultrasonic Sheet Metal Welding
* Präsentierender Autor
Zusammenfassung:Ultrasonic Sheet Metal welding (USMW) is often used in industry to join electrotechnical components, such as in welding wires or battery components. The workpieces to be welded are compressed between two machine parts : the horn and the anvil. The horn vibrates at 20 kHz, causing friction between the two workpieces which leads to a friction-induced bond. However, the process still suffers from quality fluctuations, even given the same welding parameters. The goal of this project is to better understand what factors influence the quality of the weld and to identify vibroacoustic parameters that can be used to monitor the quality of the weld during welding. To do that, a series of experiments was conducted: two thin copper sheets were welded with a welding frequency of 20 kHz. During welding, the vibrations of the horn and anvil were recorded using two laser Doppler vibrometers, as well as the acoustic emissions. The experiments also explored varying some of the process parameters, such as the amplitude of welding or the pressure applied by the horn. The data is analysed, up to the fourth harmonic, to characterise the different parts of the welding process, and compare to the strength of the welds.