Topology optimization of large ultrasonic tools for uniform vibration using level-set method

Abstract A uniform vibration distribution over the working surface of ultrasonic bonding tools is important for industrial applications, but its design requires much expertise owing to wave effects. Topology optimization using level-set functions progresses with a clear interface rather than grayscale density. Therefore, when the tools designed on the basis of optimization results are reflected in the actual fabrication, there is little error in the resonance frequency and flatness of vibration. In this study, we perform optimization to obtain a uniform vibration distribution by using commercial finite element software to create a three-dimensional model by extruding a shape obtained from a level-set function in a two-dimensional space. The tool obtained from the optimization is fabricated and the transducer performance, the vibration distribution, and the flatness of the vibration are measured.