KSHP. OMD №4-2020

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 5. Kinematic and stress state of a cylindrical plastic region located under the forming wall of the tumbler

To extrude tumblers with a conical bottom part using the A. L. Vorontsov plastic flow method, the kinematic and stress state of the extruded metal in the area of the plastic deformation zone located under the forming cup wall and adjacent to the cylindrical section of the matrix are determined. The resulting formulas will be used to determine the stress state in the areas of the source located under the end of the punch.
Keywords: die forging; metal tumbler with conical bottom part; combined extrusion; stresses; deformation.

A. E. Tsibulko, E. A. Romanenko (PJSC «NKZM», Kramatorsk, Ukraine)

Strength criterion for negative materials Poisson's ratio

A strength criterion is proposed for materials with a negative Poisson's ratio, based on the dependence of the destructive factor: normal stresses on the individual components of the specific potential strain energy.
Keywords: strength; normal stress; relative deformation; potential energy.

N. I. Sidnyaev, А. А. Fedotov, N. K. Kеsakyan (The Bauman Moscow State Technical University, Moscow)

Method of determination of diffusive and convective heat flows during pressing of non-ferrous alloy profiles

The research is devoted to the method of determination of diffusive and convective heat flows during pressing of non-ferrous alloy profiles, based on the solution of three-dimensional thermoplastic problem. General information about the process of metal pressing, the nature of the stress-strain state, temperature-speed regime are considered. Elements of technological process of pressing, design of the press tool and features of structure and properties of profiles are described. Examples of using the results of three-dimensional numerical simulation of metal flow in the design of matrices are shown.
Keywords: methods; pressing; band; profile; channel; velocity; metal; matrix.

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

The study of changing the profile parameters of large-diameter pipes during expansion using a subroutine in QForm

Finite elementary modeling of the process of expanding large-diameter pipes is described in the QForm environment, a mathematical technique with an algorithm for studying changes in the parameters of the external profile of pipes is carried out using a subroutine in the LUA language directly in QForm. In this case, the limiting movement of the segments is also determined to stop the expansion process in accordance with the condition where the plastic deformation is 1,2 % according to GOST 31447-2012 or the roundness of the pipes is minimal.
Keywords: large-diameter pipes; expansion; finite elementary modeling; subroutine; QForm.

M. A. Petrov, I. S. A. El-Deeb (Moscow Polytechnic University, Moscow)

To the development of the algorithm for the inline inspection of the geometric and technological parameters on the example of cold bulk forging of a bolt blank

The algorithm of the production line control based on the results comparing, obtained after 3D-scanning and numerical simulation, is under study. The algorithm was presented as a block-diagram and its realization was designed virtually. The necessary percentage of the machine loading on the example of the bolt blank with hexagon head based on the operation times was determined. Two scenarios were investigated within the algorithm development and the influence of the technological parameters on the geometrical parameters of the forging were shown.
Keywords: numerical simulation; optical 3D-scanning; bolt blank; cold bulk forging; digital production; production planning.