The Influence of Lateral Wall Vibrations on the Ultrasonic Welding of Thin-Walled Parts

Abstract

The welding of thin-walled thermoplastic parts by ultrasonic vibrations is often seriously impaired by variability in bond strength along the interface of the welded parts. This study shows that the strength of the weld is related to the vibrations in a direction normal to the walls of the parts. Specifically, for the typical thin-walled part studied, the strength has been found to have an inverse dependence on the amplitudes of the relative lateral motion at the interface. Free vibration experiments and finite element calculations for natural frequencies have also been conducted that provide supporting evidence of the vibration modes observed.