Investigation of the Stress-Strain State and Microstructure Transformation of Electrotechnical Copper Buses in the Deformation Zone during Continuous Extrusion

2021 ◽  
Vol 62 (2) ◽  
pp. 179-189
Author(s):  
A. N. Koshmin ◽  
A. V. Zinoviev ◽  
A. Ya. Chasnikov ◽  
G. N. Grachev
Keyword(s):  
Deformation Zone ◽  
Strain State ◽  
Stress Strain ◽  
Microstructure Transformation ◽  
Stress Strain State ◽  
Continuous Extrusion

Investigation of the stress-strain state and microstructure transformation of copper busbars in the deformation zone during continuous extrusion

2021 ◽  
Vol 1 (1) ◽  
pp. 36-48
Author(s):  
A. N. Koshmin ◽  
A. V. Zinoviev ◽  
A. Ya. Chasnikov ◽  
G. N. Grachev
Keyword(s):  
Grain Size ◽  
Plastic Strain ◽  
Deformation Zone ◽  
Strain State ◽  
Stress Strain ◽  
Deformation Heating ◽  
Stress Strain State ◽  
The Press ◽  
Metal Deformation ◽  
Continuous Extrusion

The paper describes an extensive study of features peculiar to physical and mechanical processes occurring in metal in the deformation zone during the continuous extrusion of Cu-ETP rectangular busbars 10×60 mm in size. Finite element computer simulation was used to obtain the values of extrusion power parameters. It was noted that moment and force values increase to the point of filling the press chamber free space with metal reaching a maximum of 12.26 kN·m and 1.54 MN, respectively. The stress-strain state analysis of metal in the deformation zone made it possible to obtain distribution fields of accumulated plastic strain, strain rate intensity and average stresses, and to build the graph of metal temperature variation over time during extrusion. Maximum levels of accumulated plastic strain and compressive stresses are observed in the contact zone of the workpiece with the press container abutment. The most intense metal deformation heating also occurs there. The comparison of modeling and microstructural study results indicate that a significant portion of the cast structure grinding work occurs at the entrance to the deformation zone and at the abutment zone subjected to the highest level of compression stresses. Metal deformation during the die passage leads to an oriented crystal structure formed with a grain size of 25–30 μm. Sample hardness measurement results are consistent with the results of structure analysis in the studied areas of the deformation zone. When the workpiece passes through the compression container abutment section, deformation heating occurs, which leads to a decrease in hardness from 93 to 67 HV. After the metal passes through the die, recrystallization processes continue in it leading to a slight increase in grain size and, accordingly, a decrease in hardness from 79 to 74 HV, which continues until the busbar contacts a cooling medium.

Strain and Friction Effect on the Stress-Strain State in the Deformation Zone during Cold Rolling of Thin Beryllium and Aluminum Foils

2019 ◽  
Vol 822 ◽  
pp. 716-724 ◽  
Author(s):  
Vasiliy V. Mishin ◽  
Ivan A. Shishov ◽  
Vladimir V. Paromov
Keyword(s):  
Friction Coefficient ◽  
Cold Rolling ◽  
Deformation Zone ◽  
Strain State ◽  
Hydrostatic Stress ◽  
Stress Triaxiality ◽  
Fracture Prevention ◽  
Stress Strain ◽  
Stress Strain State ◽  
Contact Arc

The effect of strain and the friction on the stress-strain state in the deformation zone during cold rolling of thin beryllium and aluminum foils was investigated in this work. Calculations showed that material hardening has a significant influence on the contact pressure distribution along the contact arc. Although it, the distributions of hydrostatic stress and stress triaxiality are favorable for fracture prevention both beryllium and aluminum except narrow regions near the entrance and the exit of deformation zone for all considered cases (strain up to 40%, friction coefficient in range 0.03 – 0.3). The most favorable stress state is observed during cold rolling with a high friction coefficient (rolling without lubrication).

scholarly journals Study of stress-strain state during cross-wedge rolling with one tool

2019 ◽  
Vol 64 (2) ◽  
pp. 175-181
Author(s):  
G. V. Kozhevnikova
Keyword(s):  
Computer Simulation ◽  
Comparative Studies ◽  
Deformation Zone ◽  
Strain State ◽  
Average Stress ◽  
Cross Wedge Rolling ◽  
Axial Region ◽  
Stress Strain ◽  
Cross Rolling ◽  
Stress Strain State

The peculiarity of cross-wedge rolling with one tool is the workpiece deformation with one tool and the fact that the workpiece is not supported with the tool from the opposite side. On both sides of the tool outside the contact with the workpiece, the workpiece is fixed with pairs of upper and lower tools, by means of which the axis of the workpiece is held in a constant position. Such conditions of rolling qualitatively change the deformation zone and, as a result, the stress-strain state.The change in the stress-strain state was qualitatively estimated by comparing the fields of slip lines in the traditional two-tools cross rolling and one-tool cross rolling. One-tool cross rolling increases the normal and average stress at the contact by 7.8–14.5 %, changes the average stress of the specimen from tensile to compressive one in the axial region. This circumstance significantly increases the resource of plasticity and allows rolling metals with limited plasticity without opening the axial cavity. Comparative studies of the stress-strain state from the traditional two-tools cross-wedge rolling and one-tool cross-wedge rolling in the axial region of the workpiece have been carried out by computer simulation.

scholarly journals DETERMINATION OF THE OPTIMAL SPEED OF THE MANDREL IN THE CONTINUOUS REELING MILL USING NUMERICAL SIMULATION

2017 ◽  
pp. 86-92 ◽  
Author(s):  
Yu. L. Bobarikin ◽  
Ya. I. Radkin
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Deformation Zone ◽  
Numerical Experiments ◽  
Strain State ◽  
Stress Strain ◽  
Optimal Speed ◽  
Stress Strain State

A proper numerical model of expanding process on a three roll continuous reeling mill was created and number of numerical experiments of the process of tubes rolling were performed. Based on the analysis of the stress-strain state of a rough tubes deformation zone, optimal speed rates of the mandrel providing the decrease in mill rolls and deterioration of mandrel which direct influences on the quality of rough tubes were determined. 

scholarly journals Stress-strain state of metal in deformation zone during production of steel section billets on the unit of combined continuous casting and deformation. Report 1

2020 ◽  
Vol 63 (7) ◽  
pp. 548-553
Author(s):  
O. S. Lekhov ◽  
A. V. Mikhalev
Keyword(s):  
Continuous Casting ◽  
Cross Sections ◽  
Deformation Zone ◽  
Strain State ◽  
Cast Slab ◽  
Stress Strain ◽  
Stress Strain State ◽  
Characteristic Points ◽  
Continuously Cast ◽  
Longitudinal Division

Volumetric problem of determining stress-strain state of metal in deformation zone during forming of three section billets from the slab by separating collars of grooved strikers on the unit of combined continuous casting and deformation was set and solved. The expediency of using such unit was justified for longitudinal division mation are given for St3sp steel. The solid-state finite elements used in calculation of stress-strain state of metal in deformation zone and dimensions of the grid are described. The results of calculation of stress-strain state of metal in deformation zone were obtained by solving the problem of elasticity by the finite element method in volumetric formulation. The results of calculation of displacements and stresses in deformation zone are given in form of graphs and tables by working surfaces in four cross sections and are presented for characteristic points. Values and regularities of distribution of axial displacements in width and length of deformation center were determined during introduction of strikers separating collars into continuously cast slab in production of three section steel billets on the unit of combined continuous casting and deformation.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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