Method for identification of the vibrational modes of a rectangular parallelepiped

Abstract

An experimental method has been developed for identifying the vibrational modes of a rectangular parallelepiped solid, based on the study of its vertex motion. This method is an important enhancement of the resonant ultrasound spectroscopy technique for determination of elastic constants. The method was tested by identifying the modes of a sample of amorphous Ni80P20. The experimental setup developed to identify the modes is also useful in finding all the resonance frequencies of a solid. This technique is used on a single crystal of YbAs to illustrate the recovery of missed modes and the improvement in accuracy of the elastic constant determination.