On the damping of ultrasonic transducersʼ components

Ultrasonic transducers are nowadays widely used in a variety of applications ranging from medical devices, actuators and receivers used in engineering, measuring instruments and equipment, to devices used in agriculture and archeology. In all applications, transducerʼs vibration behavior is under influence of material, shape, size and damping of components. To have a good reproducibility, the material properties of components must be known. Under certain frequency and by having material properties including damping coefficient of ultrasonic transducersʼ components, it is well proved that the transducerʼs vibration behaviors can be predicted. In this paper, frequency response method has been developed on the basis of modal analysis for calculation of material damping ratio of components over the range of frequency. It should be noted that metallic materials have a lower damping loss compared with non-metallic (ceramic or polymer) materials. Yet this low damping may have effect on the vibration performance of transducer. Damping curves of stainless steel 304 and aluminum 7075-T6, used normally for transducers, have been plotted over the range of frequency and this helps in determination of exact damping value of the components in any vibration frequency.