REMOTE MEASUREMENT OF THE ELASTIC PARAMETERS BY ULTRASOUND- STIMULATED VIBRO-ACOUSTIC SPECTROGRAPHY

Estimation of the Young’s modulus of metals based on the resonance frequency of a given structure has been reported previously. In some of these methods, an electromagnetic or piezoelectric actuator has been used to induce resonance in the structure [1]. The resulting response could be measured by different means, for example by a piezoelectric device. In most cases either the excitation and/or detection require some form of contact with the structure. In many applications such a contact is not desirable, either because of its loading effect or limitation in accessing the object, especially when the object under test is too small for such measurements.