Machinery & Energetics

The article presents the results of studies of the formation of a macrocrack in the falling part of the complete strain diagram using the acoustic emission method (AE). It is shown that to establish the qualitative and quantitative differences in the distribution of AE, special equipment is needed – a servo system, which makes it possible to slow down the process of destruction. The results of comparing the spectrum of the distribution of the AE counting rate and the load – time relationship on the falling portion of the strain diagram revealed the AE parameter characterizing the damage accretion observed before the formation of the macrocrack, when the transition from the discrete to the continuous AE distribution occurs, the loss of the AE signal in defects and its complete disappearance at the moment of macrocrack formation. Parameter AE, characterizing the moment of accretion of damage, proposed as the upper limit of the micro-crease and can be used to establish the stage of failure during the diagnostics of metal structures, including structures under the action of working pressure.

acoustic emission, damage kinetics, piezoelectric sensor, macrocracks, diagnostics