Vibrational property investigation in longitudinal magnetically-tuned piezoelectric ultrasonic composite transducers

Abstract This research introduced an innovative composite piezoelectric ultrasonic transducer with magnetically-tuned, enabling dynamic frequency modulation. The proposed configuration integrates three key components: a longitudinal sandwich-type piezoelectric transducer, a magnetically-tuned resonance horn assembly, and a conical horn. An electromechanical equivalent circuit model was established to analyze the transducer’s vibration characteristics. Theoretical analysis, finite element simulation using COMSOL, and experimental validation were conducted to evaluate the resonance frequency and vibrational modes under different conditions. The transducer incorporates Terfenol-D, a smart magnetostrictive material exhibiting variable Young’s modulus characteristics under externally applied DC magnetic fields through the ΔE-effect. This magneto-elastic coupling mechanism facilitates precise electromechanical resonance adjustment, achieving real-time frequency modulation within the composite transducer system. The experimental results show that as the current increases from 0.2 A to 5.2 A, the magnetic field increases from 18.58 Gs to 310.84 Gs, and the frequency of the transducer increases by 380 Hz. Experimental results demonstrate that the transducer achieved adjustable resonance frequencies in real-time. This means that the research has potential value for applications such as pesticide spraying, fertilizing, irrigation, fuel atomization, wet desulfurization, dust suppression and atomized drug delivery. This research provides a foundation for the development of advanced ultrasonic transducers with tunable frequencies for diverse industrial and environmental applications.