Development of a method for diagnosing the initial stage of material damage by the emitted acoustic field

Dynamic loading of structures of responsible use, such as power plant cases, chemical reactors, tanks, pressure vessels, etc., cause the development of damage to materials and structural elements, the initial stage of which is not detected by traditional means of flaw de-tection. As a method supplementing existing methods of defectoscopic control, a contactless remote method for monitoring changes in the spectral characteristics of oscillations of speci-mens and structural elements through changes in the acoustic field emitted by them after local shock effects is proposed. It has been experimentally established that the most structurally sensitive among other spectral characteristics is internal friction, the magnitude of which is mainly due to the energy dissipation in the material. Changes in this characteristic allow to control the initial stages of the process of structural damage to metal, while other characteris-tics retain stable values. The report presents the results of experimental studies on the effect of the level of fa-tigue damage of steel beam samples on the characteristics of the quality factor of the emitted acoustic field, operated under the same conditions, but with different terms. The technique and equipment for testing beam samples for the quality factor of free decaying oscillations with spectral analysis of the acoustic field emitted by them are presented.