A. L. Vorontsov, D. A. Lebedeva (The Bauman Moscow State Technical University, Moscow)

The study of combined extrusion of tumblers with the co-bottom part.
Part 11. Methodology for calculating technological parameters of the traditional process of cramped extrusion

A method for calculating the energy-power and deformation parameters of the traditional process of cramped extrusion of nozzles with a conical bottom part, which includes preliminary obtaining by molding the outer conical section of the bottom part of the product and the subsequent back extrusion of the glass with an internal cavity of the required geometry, is presented. The extrusion of both non-hardening and hardening material is considered. In the latter case, the account of the hardening of the extruded material is described in detail. The above formulas make it possible to determine such important parameters of the stamping process as total and specific deforming force, maximum pressure on the die wall, and increase in the yield stress.
Keywords: forging; tumblers with the co-bottom part; combined extrusion; stresses; deformations.

A. A. Pasynkov (Tula State University, Tula)

Upsetting of a flange on pipeline parts during viscoplastic unsteady deformation

Relationships are proposed for calculating the modes of isothermal stamping-upsetting of edge flanges on workpieces under viscoplastic conditions. The state of plane deformation is adopted. The energy method of solution is used in relation to the discontinuous field of displacement velocities. The pressure and the change in the solidity of the workpiece material are calculated as a function of the upsetting rate.
Keywords: viscoplasticity; power; pressure; speed; material continuity.

G. L. Baranov (The Ural Federal University named after the first President of Russia B. N. Yeltsin, Ekaterinburg)

Influence of non-uniformity of deformation on the upsetting force of the strip

Dependences are obtained for determining the upsetting force of a rectangular strip, taking into account the exact condition of von Mises plasticity and uneven deformation in the cross section of the strip. The influence of the parameters of the upsetting process on the error in calculating the upsetting force by known methods using the hypothesis of flat sections and an approximate plasticity condition is established.
Keywords: upsetting process; friction conditions; uneven deformation; contact stresses; upsetting force.

A. N. Petrov, V. E. Yefimov (Moscow Politech, Moscow)

Research into mechanical properties of pressed powder goods

This article deals with researching of the pressed powder goods. There were three powder materials such as graphite grade «P», colloidal graphite grade «С-1» and aluminum powder grade «PA-1». We studied properties of these materials after pressing with hydraulic press 10 tons in capacity. We found out that force of degradation for the pressed graphite goods grade «P» could be 114…190 kgf and depends on pressing force from up to 1500…4000 kgf/cm2 respectively. Colloidal graphite goods have fallen the pieces. The aluminum pressed goods had force of degradation more then 1800 kgf for pressing force bp to 2500 kgf/cm2. The optimal technology parameters were determined for pressing of the powder materials.
Keywords: graphite; aluminum; pressing; force of degradation; hydraulic press; colloidal graphite; particle size distribution.

S. N. Yankevich (JSC «Instrument-Making Plant Optron», Minsk, Belarus), A. T. Volochko (Institute of Physics and Technology of the National Academy of Sciences of Belarus, Minsk, Belarus)

Development and testing of the design methodology for damping elements of wheels of personal electric transport using additive technologies

The purpose of this work is to develop an airless wheel with internal suspension for an electric scooter using the research module for designing the Solidworks package and manufacturing it through additive manufacturing.
Keywords: additive manufacturing; 3D-printing; prototyping; additive technologies.

A. V. Platonov, M. A. Kumaneev, N. P. Yampurin, O. N. Starostina, G. V. Zvonarev, K. A. Shchegletov, E. S. Korshunov (Arzamas Polytechnic Institute, a branch of the Nizhny Novgorod State Technical University named after R. E. Alekseev, Arzamas)

Simulation of the processing exposure on a numerically controlled machine on the workpiece and the device

The purpose of the study is to identify the strength of the clamping device and the workpiece of the part «Fixed sponge», which is fixed in this device. The tested object is represented as a single assembly unit in the form of «device-workpiece» set installed on a vertical machining center of the BYVER630 model. The study is carried out in the T-FlexCAD program  with the application to the 3D model of the considered maximal workloads set acting on the workpiece surfaces with various cutting tools in three-dimensional axial directions and with the torques imposition. The simulation results of the studied model showed that the device, which is made with the maximal use of standard parts, has sufficient strength and stability, and the linear movements of the workpiece fixed in the device are negligible.
Keywords: processing simulation modeling; clamping device; device safety margin; the cutting forces exposure on the device and workpiece; linear movements of the device elements and workpiece.

D. B. Efremov, Nguyen Zuy Cuong (National University of Science and Technology «MISiS», Moscow)

Finite element modeling of the expanding process of large diameter pipes with an initial defect in the form of a round protrusion

The process of expanding large-diameter pipes with a shape defect in the form of a round protrusion in the welded joint zone is investigated. Finite element modeling has been completed in the QForm environment. The analysis of the metal flow of a workpeice of an irregular initial shape was carried out with a study of the dynamics of changes in the geometric parameters of the outer profile of pipes and fixing a number of criteria. To optimize the expansion process and improve the quality of pipes, several alternative options for choosing the moment of stopping the segments are given, a “coefficient of residual elasticity” is proposed, it is possible to take into account the current technical specifications, or the requirements of GOST 31447–2012.
Keywords: large diameter pipes; expansion; finite element modeling; QForm.