Characterising the nonlinear dynamics of power ultrasonic systems

Laboratory and semi-industrial scale research have demonstrated that high power ultrasonic technology can be successfully applied to a variety of environmental, industrial and medical applications. It is known that the full scale-up of ultrasonic devices is hampered by the nonlinear vibration behaviour exhibited at high power. This paper investigates experimentally the nonlinear dynamic characteristics exhibited by an ultrasonic transducer of the Langevin type for industrial processing. Nonlinear mechanisms affecting the transducer performance such as modal interactions and response saturation are identified and characterised. Furthermore, a redesign strategy aimed at reducing the nonlinear behaviour of the power transducer is proposed. The results stemming from this work can be used for enhancing the design of ultrasonic devices powered by Langevin transducers.