Abstract

The Adhesive Mechanism of Hysteretic Nonlinearity for Media with Cracks

A.Radostin, V.E.Nazarov (Institute of Applied Physics RAS, Nizhny Novgorod, Russia)

e-mail: radostin@hydro.appl.sci-nnov.ru

The creation of models of different defects (dislocations, cracks etc.) and construction of state equations for solids containing such defects, is one of modern problems of nonlinear acoustics and seismic-acoustics. Its urgency is conditioned by the fact that acoustic properties of similar defects, as a rule, strongly differ from each other, and the nonlinearity of solids containing such defects, considerably exceeds nonlinearity of homogeneous media and materials. This circumstance creates favorable capabilities for nonlinear acoustic diagnostics of both single defects in solids, and solids containing a great number of such defects. In this work the mechanism of hysteretic nonlinearity of solids containing a crack with surfaces having an adhesion is offered. The hysteretic state equation for a rod containing a great number of such cracks is obtained. On the basis of this equation the nonlinear effects that arise during the propagation and interaction of longitudinal elastic waves in such rod are investigated. The results of this work might be useful in data processing of experimental researches in different microinhomogeneous media. The study was supported by the Russian Foundation for Basic Research (projects No 01-05-64417, No 00-05-64252).

Section : 3