Abstract

Experimental Investigation of Strain Waves in Solids

V.M.Rodyushkin, A.I.Potapov (Mechanical Engineering Research Institute of Russian Academy of Sciences, Nizhny Novgorod, Russia)

e-mail: apotapov@sandy.ru

A lot of the experimental data on investigation of dynamic behaviour of granular media and crack-containing materials at high speeds of deformation cannot be explained within the scope of the classical mechanics. Complex dynamic behaviour of these materials is conditioned by the existence of intrinsic space-time scales in matter: size of grain, lattice period, etc. On the other hand, it is necessary to measure the physical and mechanical characteristics of a material using the correlation between structural characteristics of a material and characteristics of elastic waves. The most common methods for nonlinear acoustic diagnostics are based on measurements of the dependence of elastic wave velocity on external stress, or on measurements of wave amplitudes. The experiments are carried out using continuous monochromatic waves. The method applied is based on the parametric interaction of ultrasonic wave with the field of deformation inside the material [Rodyushkin V.M. Elastic wave interaction as a principle of vibration measurement. Ultrasonics, 1995, V. 33, No. 6, P. 437-439] and impact excitation on the Kolsky apparatus [Potapov A.I., Rodyushkin V.M. Experimental study of strain waves in materials with a microstructure. Acoustical Physics, 2001. V. 47(3). P.347-352]. The research described in this paper was made possible by RFBR (grants N 00-02-16582 and N 01-01-00386).

Section : 3