Perederko A. Development of vibration test methodology and improvement of vibration measurement tools for complex equipment

Dissertation for acquisition of the scientific degree Doctor of Technical Sciences by specialty 05.11.01 – "Devices and methods for measurement of mechanical quantities". – State University of Intellectual Technologies and Communication, Odessa – 2021. The dissertation is dedicated to the improvement of methods and means of measuring the mechanical vibration signal, as well as solving the problem of building an autonomous system with improved metrological characteristics for measurement, registration of vibration parameters in vibration diagnostics and vibration tests in technical systems. In the dissertation work for the first time an adaptive mechanical filter was developed as a part of the measuring channel, which prevents the influence of high-frequency vibrations on the piezoelectric accelerometer and prevents the destruction of its sensitive element during shock tests. The method of providing frequency and dynamic ranges and accuracy of dynamic measurements of shock signals without the use of signal switching in the measuring channel is substantiated, which allows to perform measurements without additional switching operations in attenuators. To reduce the error of measuring the acceleration caused by changes in ambient temperature, the design of a piezoelectric accelerometer with a compensation device and a control system was developed for the first time. The use of structural methods to ensure a dynamic measurement process and algorithms in the development of measuring instruments for the study of vibration and shock processes in technical facilities in a wide range of temperature and mechanical effects on the primary transducers of measuring instruments and the object of study based on high-speed "sigma" -delta "ADC, filtering algorithms and signal recovery using methods that using wavelet transform. To ensure the fulfillment of vibration tests, a hydraulic vibrating stand with piezoelectric actuators in hydraulic flow control was developed for the first time. The expediency of designing actuators based on piezoelectric effect for high-speed electromechanical drives of the control system of hydraulic vibrating stands has been further developed. Key words: piezoelectric accelerometer, measuring channel, vibration diagnostics, charge amplifier, vibrating stand.