Papers by Author: Adam Kotowski

Abstract: The paper presents the use of the autocorrelation function for the description of vibrations and the problems connected with. The proposed method is based on the analysis of vibration signal recorded for machine during its operations using an analytic form of the autocorrelation function. The parameters are obtained using a curve fitting procedure. To keep a quality of parametric representation of considered vibration, only the curve fitting causes a determination coefficient over 0.90 is taken into consideration. Therefore, the autocorrelation functions are submitted for the fast Fourier transform to be helped, in determination of number of the dominant harmonic components. Also, the analytic form and parameters of power spectral density has been also calculated. Finally, the set of parameters has been collected to describe the selected fragment of vibration of the simple rotating machine. The influence of duration of analyzed vibration on the parameters values is also examined in this work.

Abstract: The paper describes a method of analytic description of impulse response (IR) signals obtained during the test of technical object. The proposed description is based on the curve fitting to obtain the values of the parameters of analytic form of auto-correlation and power spectral density function. The impulse excitation is given into thoroughly described points of object and the proper fragment of IR is selected in the order to assure the accuracy of the curve fitting over the level of 90%. This approach enables to describe changes of IR signals in the form of percentage variations in the parameters of the auto-correlation and power spectral density function (e.g. changes from the object damage).