Development of a bolt-clamped Langevin-type transducer for operation at a high frequency of 80 kHz

Bolt-clamped Langevin-type transducers (BLTs) are common vibration sources in high-power ultrasonic applications such as ultrasonic plastic joining. In this paper, the authors propose a low-aspect-ratio BLT shape based on numerical solutions of the elastic contact problem concerning the bearing stress (prestress) imposed on the interfaces between the parts by clamping with the screw bolt. It is found that the screw pitch of the clamping bolt heavily affects the stress distribution in the simulation using the finite element method. The newly developed BLTs with a high resonance frequency of approximately 80 kHz has a relatively wide radiating face and sufficient volume ratio of the piezoelectric elements that convert electrical energy into mechanical one. The average of their measured mechanical quality factors (Q) exceeds 800 despite their high resonance frequency