Actual Problems in Machine Building 2019 Vol. 6 No. 1-4

Актуальные проблемы в машиностроении. Том 6. № 1-4. 2019 Инновационные технологии в машиностроении ____________________________________________________________________ 65 ABOUT SOME ULTRASONIC TECHNIQUES FOR ASSESSING TECHNICAL CONDITION OF EQUIPMENT Ilyahinsky A.V ., Senior researcher, e-mail: ilyahinsky-aleks@bk.ru Rodyushkin V. M., D.Sc. (Engineering), Head of Laboratory, e-mail :vlkn2005@yandex.ru Institute of mechanical engineering problems RAS, 85 Belinsky st., Nizhny Novgorod, 603024, Russian Federation Abstract The article describes the possibilities of ultrasonic testing due to the uniqueness of elastic waves. The prototype of the device for monitoring of metal by Rayleigh waves in the conditions of production was developed. A pair of wedge transducers, which allowed generating and detecting the signal of ultrasonic surface waves, were used in the prototype for measuring the acoustic nonlinearity. Acoustic nonlinearity was measured as the ratio of the first and second harmonics amplitudes. Using this technique, the nonlinearity parameters are obtained over same samples made from five steels. Keywords elastic waves, identification, damage, nonlinearity.