KSHP. OMD №12-2023

Published on 06 March 2024
Written by kshp. omd Hits: 1295

A. I. Kanareykin (Russian State University for Geological Prospecting (MGRI), Moscow)

Investigation of the stress concentration of an angular incision using the functions of a complex variable

The work is devoted to the measurement of stresses. This article presents an analytical method for studying the stress concentration in the vicinity of an angular incision. The study of the stress state in this area is connected with the consideration of the problem for a composite wedge, which in the framework of the classical theory of elasticity can have singular solutions with infinite stress values at its vertex. The approach proposed in this paper to determining the laws of stress measurement in the regions of gradients is based on solving the plane problem of elasticity theory by methods of functions of a complex variable.
Keywords: stress; complex variable function; elasticity theory; stress function; angular incision.

 

A. I. Kanareykin (Russian State University for Geological Prospecting (MGRI), Moscow)

Contact-deformed state during free cutting of metals

The work is devoted to the issues of determining the contact loads of the cutting tool. It studies the contact-deformed state during free cutting of metals. The article also shows the derivation of the formula for determining the length of the contact. It is established that an approximate solution is possible only with a large number of assumptions that significantly reduce the accuracy of the calculation. In this regard, the most accurate data on the operating contact loads are obtained mainly experimentally.
Keywords: cutting processing; contact loads; cutting wedge; friction force; chip shrinkage.

 

M. S. Yashin, D. V. Kapitanenko, E. Yu. Letnikova (All-Russian scientific research institute of aviation materials, Moscow)

Full technological cycle of small-scale production of strips of solder on a nickel and copper-nickel basis at the Duo-Quarto «300» rolling mill

The development of a complete metallurgical cycle for the production of strips from solders VPr1, VPr4, VPr7 was carried out in present study. The technology worked out in the conditions of the National Research Center «Kurchatov Institute» – VIAM includes the smelting of ingots, mechanical processing, hot rolling, heat treatment and final cold rolling. The results of atomic emission chemical analysis showed a satisfactory quality of the products obtained.
Keywords: rolling; deformation; pressure treatment; solders.

 

S. A. Tipalin (Moscow Polytechnic University, Moscow)

Features of straightening bimetal by tension

Tensile straightening is used to combat distortions in complex profile shapes and sheet metal parts that occur due to residual stresses resulting from previous forming operations. The sheet metal is stretched to the point of plastic deformation, and the resulting stresses in the metal are equalized over the entire cross-section, reaching the yield point. This happens if the entire section has the same properties and the transition to the plastic state occurs under the same conditions. During unloading, residual stresses practically do not arise. However, for bimetal this straightening method is unacceptable due to the difference in properties during plastic deformation and elastic unloading; As a result, dissimilar residual stresses arise in different layers, which lead to warping of the semi-finished product. The work presents formulas by which these stresses can be calculated, as well as determining the limiting ratio of the thicknesses of bimetal layers at which the unloading theorem works.
Keywords: stretch straightening; bimetal; residual stresses; elastic deformation; sheet metal.

 

A. K. Onischenko (Salyut Machine-Building Production Association, Moscow)

Study of technological plasticity of titanium ortho-alloy VIT1 and determination of optimal temperature ranges for its deformation

It is shown that the study of the technological plasticity of the alloy VIT1 draught tests according to GOST 8817–82 does not allow to establish the quality of the metal as a whole, and its optimal technological hot deformation parameters. The most effective method studies of technological plasticity of the alloy in forging Temperatures is a TPO method. Investigation of mechanical properties and Structure at forging temperatures established initiation plastic deformation in the alloy VIT1 cracking grain boundaries. The results of the studies do not allow recommend the use of Ø 45 mm VIT1 alloy bar for any GTE parts and point to the need for further research ortho-titanium alloys in order to determine the optimal quality thermomechanical parameters of their hot processing.
Keywords: ortho-alloy VIT1; technological plasticity; TPO method; cracks along the grain boundaries.

 

Sosenushkin E. N., Rogulin S. A., Gusev D. S. (MSTU «STANKIN», Moscow)

Modeling of the rolling process of a profiled workpiece for stamping a wrench forging

The operation of rolling a pre-shaped billet for stamping a wrench forging is studied using computer simulation in the DEFORM–3D software package based on the finite element method. Such stages as: forging design, calculation and selection of the initial billet, design of tool models for a computer experiment, preparation of initial data, positioning of objects for modeling, study of rolling in oval and round calibers, analysis of the results have been implemented.
Keywords: original billet; forging, rolling; caliber; computer simulation; stress-strain state; force; temperature.