A new experimental method to estimate viscoelastic properties from ultrasonic wave transmission measurements

We develop a new experimental method to estimate viscoelastic properties of a sample by ultrasonic wave transmission. Viscoelastic properties are generally described by the frequency dependent phase velocity v ( f ) and the quality factor Q ( f ) . In order to estimate v ( f ) and Q ( f ) from waveform data obtained by the ultrasonic wave transmission method, it is necessary to correct the data for the effects of dynamic response of the source and receiver transducers and of the wave diffraction caused by finite size source. A practical method to perform these corrections based on the theoretical models is developed. The validity of the present method is demonstrated by applying it to the experimental data for stainless steel sample ( Q ⪢ 200 ), acrylic plastic sample ( Q ∼ 100 ), and partially molten organic polycrystal sample ( Q < 10 ). In comparison with the other existing methods, the present method has the advantage of not requiring any reference waveform. Using the results of this study, we discuss the validity of the reference method.