Vibrations in engineering and technology

Matviychuk Viktor – Doctor of Technical Sciences, Full Professor, Head of the Department of Electric Power Stations and Systems of the Vinnytsia National Agrarian University (3 Soniachna St., Vinnytsia, 21008, Ukraine, email: vamatv50@gmail.com)

Kolisnyk Mykola – Postgraduate Student of Vinnytsia National Agrarian University (3 Soniachna St., Vinnytsia, 21008, Ukraine, email: kolisnik30@gmail.com)

The article presents the results of the development and research of the combined technological process of forming the outer and inner flanges of the lids of fractional and distillation columns on sheet blanks by the method of stamping by rolling and rotary drawing. For this purpose, equipment has been developed that allows to form both outer and inner flanges of the blank in one run of the conical roll.

Studies have shown that technological capabilities of the process are limited by the risk of destruction of the top layers of the outer flange bending center and its corrugation, as well as by the neck formation or destruction of the peripheral areas of the inner flange. To assess the deformability of the outer flange, the stress-strain state of its bending center was investigated. According to the set stress values, the stress state of the material is determined, the maximum value of which on the surface of the bending zone is   Formula for determining the minimum radius of the mandrel, which when using the values of the critical ductility of the material allows to prevent destruction. As well, an expression for determining the maximum width of the flange, provided that the destruction of peripheral areas is prevented, is obtained.

As corrugations formation is the main danger in forming the external flanges by the stamping by rolling method (SR), the expression for determining the maximum width of the flange under the condition of a stable process is obtained. If it is necessary to get more developed flanges, it is proposed to provide thinning of their walls by rotary extraction at the second stage.

When forming the inner flanges of the blank stacks radial compressive stresses and tangential tensile stresses in the material are brought about. The action of tangential stresses causes loss of stability of the flange by way of neck formation. The value of the critical strains increases with the approach to the state of plain-strain deformation. Therefore, it is recommended to develop process parameters based on construction of the critical strains diagrams.

1. Mogilny N.I. (1983). Rotational drawing of shell parts on machine tools. Mashinostroenie. [in Russia].

2. Matviichuk, V. A., Aliyev, I. S. (2009). Sovershenstvovanie processov lokal'noj rotacionnoj obrabotki davleniem na osnove analiza deformiruemosti metallov: Monografija [Improvement of processes of local rotary pressure treatment on the basis of the analysis of metal deformability: Monograph]. Kramatorsk: DGMA [in Ukrainian].

3. Popov E.A. (1977). Foundations of the theory of sheet stamping. Mechanical. [in Russia].

4. Barkaya V. F. (1976). Forming sheet metal. Metallurgy. [in Ukrainian].

5. Barkaya V.F., Ruzanov F.I. (1973). Determination of the critical width of the flange during rotary rolling of cylindrical shells. Forging and stamping production. [in Russia].

6. Del G.D., Osipov S.S. (1987). Limiting deformations in the formation of parts from a sheet. Izvestiya vuzov. Aviation technology. [in Russia].

7. Kaletnik, G. (2013) Osnovy inzhenernykh metodiv rozrakhunkiv na mitsnist i zhorstkist [Basic engineering methods of rosrahunkiv on the city and the market] Kiev: “High-Tech Press” [in Ukrainian].

8. Sivak, R. (2017). Evaluation of metal plasticity and research on the mechanics of pressure treatment processes under complex loading. Eastern-European journal of enterprise technologies. [in English].