Kosmach O. Monitoring and diagnosis of friction units with composite materials using by acoustic emission method

The object of study is the phenomenon of acoustic radiation, which occurs at friction and wear surfaces with composite materials. The subject of research is the methods to improve the reliability of acoustic emission control units of friction with composite materials. Firstly the model signal of acoustic emission during fracture of composite material by shear force, which takes into account the kinetics of mechanical destruction of its elements was created. The factors that influence the development process of the destruction of composite material and parameters of acoustic emission signals were determined. Firstly the model of the acoustic emission signal resulting friction surfaces of composite materials which is based on a model of pulse acoustic emission signals, which are formed during fracture surfaces of composite materials as well as the dynamics of change of contact interaction surface area of friction unit. The factors that affect the on friction surface frictional contact of composite materials and the resulting parameters of acoustic emission signals were determined. The influence of operating parameters of friction unit which define the conditions of friction and wear on its surfaces, as well as patterns of the resulting parameters of acoustic emission signals were determined. It has been shown that the informative parameters of the resulting acoustic emission signals that are sensitive to the processes of catastrophic fracture surface frictional contact with the composite materials of the frictional interaction and temperature in the zone of frictional contact is, therefore, the variance of the total energy, average energy and averaged amplitude. New methods of control of friction units: the definition of catastrophic destruction frictional contact surfaces of composite materials which is based on the processing and analysis of the rate of change of the variance of the total energy of the resulting acoustic emission signals, the definition of frictional interaction between surfaces of composite materials which is based on the processing and analysis of the average energy the resulting acoustic emission signals, determine the temperature in the zone of frictional contact which is based on the processing and analysis of the average amplitude of the resulting acoustic emission signals.