Evaluation of the influence of the reaction rate of the thermodynamic subsystem on the dynamics of the cutting process in metalworking

OBRABOTKAMETALLOV Vol. 23 No. 2 2021 28 TECHNOLOGY Evaluation of the in fl uence of the reaction rate of the thermodynamic subsystem on the dynamics of the cutting process in metalworking Victor Lapshin a, * , Roman Rusanovsky b , Ilya Turkin c Don State Technical University, 1 Gagarin square, Rostov-on-Don, 344000, Russian Federation a https://orcid.org/0000-0002-5114-0316 , lapshin1917@yandex.ru , b http://orcid.org/0000-0001-9408-5188, zames161@yandex.ru , с https://orcid.org/0000-0003-4792-4959, tur805@mail.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 2 pp. 17–30 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.2-17-30 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 14 January 2021 Revised: 24 February 2021 Accepted: 14 April 2021 Available online: 15 June 2021 Keywords : Nonlinear dynamics Vibrations Cutting process Cutting temperature Funding This study was performed with fi nancial support of RFBR grant № 19-08-00022. ABSTRACT Introduction. Modern metalworking machines with CNC, allow to achieve a qualitatively new level of metal processing by cutting in metal turning. At the same time, it is possible to achieve the required shape, dimensional accuracy, as well as the relative position of the surfaces of the part, but such an indicator of the processing quality as the roughness of the treated surface, associated with the vibration activity of the tool, does not always meet the speci fi ed requirements. The factor determining the vibration mode of cutting in a metal-cutting lathe is the self- excitation factor of the cutting system, which is caused by additional feedbacks formed during the cutting process, one of which is the thermodynamic subsystem of the cutting system, which is the subject of research . Purpose of the work : due to the formation of a consistent model of the relationship between the subsystems that describe the force, heat and vibration reactions of the tool, an adequate description of the mechanism for reducing the vibration load on the cutting process is obtained. The paper studies the process of metal turning on metal-cutting machines with a detailed description of the interaction between the thermodynamic, power and vibration subsystems of the cutting system. Research methods : full-scale and numerical experiments in which the Matlab package of mathematical programs is used for data processing and analysis. Results and discussion . The results of full-scale and numerical experiments are presented, in particular, graphs of coordinate changes describing tool deformation, and data sets are obtained that re fl ect the dependence of the vibrational energy of tool movements on the reaction time of the thermodynamic subsystem of the cutting system. A qualitative assessment of the results of a full-scale experiment allows us to con fi rm the adequacy of both the model itself and the results of its modeling. The scope of application of the results obtained in the study is related to the possibility of preliminary preparation of the cutting wedge, which will provide a set value of the time constant of the thermodynamic subsystem, which in turn ensures the minimization of vibration energy. Conclusion : the mathematical model proposed in this paper adequately describes the mechanism of temperature in fl uence on the vibration load of the turning process. For citation: Lapshin V.P., Rusanovsky R.V., Turkin I.A. Evaluation of the in fl uence of the reaction rate of the thermodynamic subsystem on the dynamics of the cutting process in metalworking. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 2, pp. 17–30. DOI: 10.17212/1994-6309-2021-23.2-17-30. (In Russian). ______ * Corresponding author Lapshin Viktor P., Ph.D. (Engineering), Associate Professor Don State Technical University, 1 Gagarin square 344000, Rostov-on-don, Russian Federation Tel.: 8 (900) 122-75-14, e-mail: lapshin1917@yandex.ru References 1. Grabec I. Chaos generated by the cutting process. Physics Letter A , 1986, vol. 117, no. 8, pp. 384–386. DOI: 10.1016/0375-9601(86)90003-4. 2. Lapshin V.P., Tyunyaev R.A., Khristoforova V.V. [Evaluation of the effect of the feed rate on the equilibrium modes of the drive providing milling of the workpiece of variable thickness]. Dinamika tekhnicheskikh sistem , DTS- 2015 [Dynamics of technical systems], Rostov-on-Don, 2016, pp. 180–184. (In Russian). 3. Reznikov A.N., Reznikov L.A. Teplovye protsessy v tekhnologicheskikh sistemakh [Thermal processes in technological systems]. Moscow, Mashinostroenie Publ., 1990. 288 p.