Intrinsic eigenvibration frequency in the resonant ultrasound spectroscopy: Evidence for a coupling vibration between a sample and transducers

摘要

The resonant ultrasound spectroscopy enables us to measure elastic constants of various materials with high accuracy. One of its curious features is resonance frequency shift caused by modulation of clamp force for a sample, although its mechanism has not been clarified yet. A coupling vibration model is newly proposed to interpret this phenomenon and predict its functional form. Further, it is confirmed that the resulted functional forms depend on characteristics of each eigenvibration mode. The extrapolation based on those functional forms enables us to correct measured frequency to the intrinsic one with improved accuracy at least by one order of magnitude. Thus the correction is essential in order to obtain accurate derivatives of frequency with respect to temperature, pressure, composition, and so forth.