METHODS OF ACOUSTIC EMISSION ESTIMATION OF NANO-CHARACTERISTICS OF THE STRENGTH OF STRUCTURAL AND ENGINEERING MATERIALS OF THE OBJECTS

Abstract

The acoustic emission method is the most promising metrological basis for non-destructive testing of strength. The necessity of solving problems of acoustic emission prediction of fracture and the ambiguity of the connection of the results of acoustic emission tests makes the problem of modeling strength heterogeneity relevant; it suggests a transition to a more complex level of research. The complexity of predicting the behavior of heterogeneous materials necessitates modeling and determining the parameters of the fracture process at the nano-defining operational level and the need to interpret the Kaiser effect revealing the strength heterogeneity as a phenomenon of a decrease in the activity of elastic radiation upon application of repetitive loads on the object under control. Heterogeneity modeling requires determining of its type, criterion and approach to estimation. The type of heterogeneity depends on the solved problem and has to be associated with the property that determines the function of real objects. Also, the criterion should be informative and the method of its evaluation should be non-destructive. Examples of modeling the temporal dependences of the AE parameters under conditions of strength heterogeneity are given, the analysis is carried out and the Kaiser effect is estimated from the point of view of a multilevel model of the dependences of the temporal parameters of acoustic emission.