Automated design and optimization of rectangular plate sonotrodes for squeeze film levitation

The careful handling of sensitive workpieces is constantly gaining importance in production engineering. Ultrasonic non-contact handling through Squeeze Film Levitation (SFL) is thereby a rather new and promising approach. The required ultrasonic systems consist of well known parts, like an ultrasonic transducer, an ultrasonic horn and a manipulator. As manipulators, either tonpilz sonotrodes are used for small workpieces or rectangular plate sonotrodes for larger workpieces. So far, only very little research has been conducted on the design of the latter one. In the paper at hand, an automated design and optimization process for rectangular plate sonotrodes considering the specific demands of the SFL on the mode shape is presented and validated. After summarizing the basics of the squeeze film levitation as well as outlining the existing models and design approaches for the required components, the automation procedure with a simple optimization algorithm is introduced. Following a description of the employed finite element model, the Modal Assurance Criterion (MAC) for the mode-tracking is introduced. Since the objective function of the optimization problem also uses the MAC for the evaluation of the mode shape, the synthesis of an idealized mode vector is described. Finally, the automated design and optimization process is validated through the experimental analysis of an exemplary plate sonotrode. copy; KRISHTEL eMAGING SOLUTIONS PVT. LTD.