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 Numerical and experimental investigations of steel-concrete beams with thin-walled section

Vestnik MGSU ◽  
2019 ◽  
pp. 22-32
Author(s):  
Farit S. Zamaliev
Keyword(s):  
Experimental Data ◽  
Computer Simulation ◽  
Strain State ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Stress Strain ◽  
Stress Strain State ◽  
Numerical Studies ◽  
Field Samples ◽  
Thin Walled

Introduction. Conducted is to the evaluation of the stress-strain state of the steel-concrete beams with thin-walled section. In recent times, steel-reinforced concrete structures have become widely used in civilian buildings (beams, slabs, columns). Thin-walled section have not found wide application in steel concrete structures, unlike steel structures. Presents the results of numerical studies of beams consisting of concrete, anchors and steel beams. Two investigating of the location of anchors are given. Numerical investigations are presented of steel-concrete beams with thin-walled section based on numerical studies. Testing procedure and test result are given. Results of calculations, comparison of numerical and experimental studies are presented. Materials and methods. For full-scale experiments, steel I-beams with filling of side cavities with concrete were adopted, screws are used as anchor ties, with varied both the lengths and their location (vertically and obliquely). As steel curved C-shaped steel profiles were used steel profiles from the range of the company “Steel Faces”. ANSYS software package was used for computer modeling. A total of 16 steel concrete beams were considered, for which the results of strength and stiffness evaluation were obtained in ANSYS. Results. The data of the stress-strain state of beams on the basis of computer simulation are obtained. The results are used for the production of field samples. Data of computer simulation are compared with the indicators of field experiments. Conclusions. The stress-strain state of steel-concrete structures was studied on the basis of numerical and experimental data. The proposed calculation method gives good convergence with the experimental data. Anchor connections made from self-tapping screws can be used in studies for modeling in steel-concrete beams structures and other anchor devices, ensuring the joint operation of concrete and steel profiles in structures.

Modeling of “Stretching-Over” Static-Dynamic Process

2021 ◽  
Vol 1031 ◽  
pp. 216-221
Author(s):  
Irina A. Belyaeva ◽  
Vladimir Glushchenkov ◽  
A.Y. Pyl'tsin
Keyword(s):  
Magnetic Field ◽  
Computer Simulation ◽  
Dynamic Process ◽  
Strain State ◽  
Distribution Patterns ◽  
Pulsed Magnetic Field ◽  
Magnetic Pulse ◽  
Stress Strain ◽  
Stress Strain State ◽  
Stretching Process

The article presents the technological scheme of the “stretching-over” hybrid technology, when the workpiece is simultaneously affected by two sources of loading: static and dynamic. It is proposed to use a pulsed magnetic field as a dynamic load. In this case, the tightening punch is equipped with an inductor connected to a magnetic-pulse unit. As a result of computer simulation, the distribution patterns of the stress-strain state in a tight-fitting workpiece were obtained both in the case of a conventional tight-fitting and with the proposed hybrid one. It was found that exposure to a pulsed magnetic field changes the stress-strain state, making it possible to intensify the stretching process.

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.

scholarly journals Investigation of the Tubular and Cylindrical Billets Stamping by Rolling Process with the Use of Computer Simulation

2021 ◽  
Author(s):  
Viktor Matvijchuk ◽  
Andrii Shtuts ◽  
Mykola Kolisnyk ◽  
Ihor Kupchuk ◽  
Iryna Derevenko
Keyword(s):  
Computer Simulation ◽  
Computer Modeling ◽  
Strain State ◽  
Cold Deformation ◽  
Rolling Process ◽  
Stress Strain ◽  
Workpiece Material ◽  
Deformation Curves ◽  
Stress Strain State ◽  
Sound Management

Forming of blanks during stamping by rolling (RS) is possible according to technological schemes of deposition, landing, direct and reverse extrusion, distribution and compression, etc. Controlling the relative position and shape of the deformed tool allows you to control the direction of flow of the workpiece material and the nature of its formation, as well as the stress-strain state of the material. The complexity and versatility of RS processes necessitate computer modeling for sound management of basic technological parameters.Physical experimental as well as computer modeling of the RS process in the DEFORM-3D software package was performed in the work.According to the results of computer simulation, the distribution of deformation components, stresses and temperatures in the deformed workpiece area was obtained, and using the Cockroft-Latham criterion, the destruction of metals during cold deformation was also predicted.Physical modeling of the SR process on lead blanks confirmed the nature of their deformation, obtained by computer simulation. And the analysis of the stress-strain state of the material based on the results of measurements of the deformed grid confirmed the validity of the appointment of boundary conditions in computer simulation.This approach is suitable for modeling by the method of SR of any metal models, for which it is necessary to know their mechanical characteristics, including boundary deformation curves.

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