ACOUSTIC METHOD FOR CONTROL OF SUB-SURFACE STRESSES IN SOLID MEDIA

摘要

The invention relates to ultra-sonic engineering of control. Acoustic method of control of subsurface stresses in solid media is in fact that by means of acoustic transformer one introduces into controlled object longitudinal acoustic vibrations in two normal to each other main planes at angle of incidence value of which is close to value of first critical angle, one receives at same angle non-mirror reflected long sub-surface acoustic vibrations in stressed object and at absence of stresses one measures respective velocities of propagation of longitudinal subsurface acoustic vibrations, and with application of acoustic ratios one determines values and signs of stresses in under-surface layers of object with account of elastic-acoustic characteristics of material that are determined by calculation or in experimental way by loading sample of material. Value of velocity of propagation of longitudinal subsurface waves in direction of effect of stresses uniquely depends on level of those stresses, and so invention makes it possible to control values and signs of stresses in subsurface layers of object and increase accuracy of control of stressed state of object as whole.