Ignat'ev Aleksandr Anatol'evich, Doctor of engineering sciences, professor, sub-department of automation, control, mechatronics, Yuri Gagarin State Technical University of Saratov (77 Politekhnicheskaya street, Saratov, Russia), email@example.com
Samoylova Elena Mikhaylovna, Candidate of engineering sciences, associate professor, sub-department of automation, control, mechatronics, Yuri Gagarin State Technical University of Saratov (77 Politekhnicheskaya street, Saratov, Russia), firstname.lastname@example.org
Ignat'ev Stanislav Aleksandrovich, Doctor of engineering sciences, professor, sub-department of automation, control, mechatronics, Yuri Gagarin State Technical University of Saratov (77 Politekhnicheskaya street, Saratov, Russia), email@example.com
Background. The dynamic quality of machine tools, greatly influencing the geometric parameters of precision and the physical and mechanical characteristics of the surface layer of parts, is based on the measurement of vibro-acoustic (VA) oscillations. The subsequent treatment thereof is aimed at determining the spectral, correlation and other characteristics, on the basis of which the technical condition of machines and the designated mode of cutting are assessed in terms of quality and productivity of part machining. It is very important to select and substantiate informative characteristics, based on the measurement of the dynamic oscillations of the VA (DS) system of a machine when cutting, which allows to set a suitable processing mode. This mode is set by the maximum margin of DS stability, determined by the transfer function, which, in turn, is determined from the autocorrelation function (ACF), VA oscillation nodes involved in the forming process. The work is topical as the construction of an analytical model of the autocorrelation function (ACF) of VA oscillations of DS is important from the point of view of the subsequent comparison with the experimental ACF, calculated from measurements of vibrations on the machine and used subsequently for determination of the DS stability margin
serving a machine tool’s dynamic quality estimate.
Materials and methods. To calculate the ACF VA oscillations in DS of metalcutting machine tools the authors used its connection with the spectral density of the input “white noise” signal power and the frequency response of the machine tool’s DS.
Results. Analytically, using the theory of residues the authors obtained an expression for the ACF VA oscillations in the machine tool’s DS in the form of a damped cosine curve. The expression was similar to the one identified by experimental data of VA oscillations measurement.
Conclusions. The constructed theoretical model of the ACF VA oscillations of the gridning machine’s DS is adequate to the ACF derived from the experimental data, which makes it possible to prove the feasibility of its use for calculation of the transfer function of the machine tool’s DS with subsequent evaluation of its safety factor.
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