scholarly journals Modeling of the stamping process of box-type forging

2020 ◽  
Vol 315 ◽  
pp. 11002
Author(s):  
Vagid Kadymov ◽  
Evgeny Sosenushkin ◽  
Elena Yanovskaya
Keyword(s):  
Mathematical Model ◽  
Contact Pressure ◽  
Nonlinear Partial Differential Equations ◽  
Plastic Layer ◽  
Normal Stresses ◽  
Outer Contour ◽  
Bottom Part ◽  
Deformed State ◽  
Thin Plastic ◽  
Single Boundary

A new mathematical model for manufacturing rectangular of box-type forgings is proposed. Along the outer contour of the forging there are walls with thickness comparable to the thickness of the bottom part of the forging. To calculate the power parameters of the technological process under study, the authors use the theory of flow in a relatively thin plastic layer as described by A. A. Ilyushin. A thickness-averaged two-dimensional mathematical model of the plastic layer spreading process is described by nonlinear partial differential equations of the first order with respect to the contact pressure and the flow velocity components. For a metal that is in a flat deformed state, the condition of complete plasticity is assumed, under which the tangent stresses in the layer are small in comparison with normal stresses and they can be ignored, and two normal stresses in the cross section can be considered equal in the first approximation. The third normal stress is equal to the contact pressure of the layer on the tool. In this case, it is sufficient to set a single boundary condition on the border of the regions.

scholarly journals RESEARCH OF THE TENSELY-DEFORMED STATE OF ELEMENTS OF MOBILE HEAT STORAGE

2020 ◽  
Vol 42 (2) ◽  
pp. 68-75
Author(s):  
V.G. Demchenko ◽  
А.S. Тrubachev ◽  
A.V. Konyk
Keyword(s):  
Mathematical Model ◽  
Heat Storage ◽  
Quantitative Estimation ◽  
The Real ◽  
State Of The Union ◽  
Real Geometry ◽  
Deformed State ◽  
The Mathematical Model ◽  
Minimization Of Functional

Worked out methodology of determination of the tensely-deformed state of elements of mobile heat storage of capacity type, that works in the real terms of temperature and power stress on allows to estimate influence of potential energy on resilient deformation that influences on reliability of construction and to give recommendations on planning of tank (capacities) of accumulator. For determination possibly of possible tension of construction of accumulator kinematics maximum terms were certain. As a tank of accumulator shows a soba the difficult geometrical system, the mathematical model of calculation of coefficient of polynomial and decision of task of minimization of functional was improved for determination of tension for Міzеs taking into account the real geometry of equipment. Conducted quantitative estimation of the tensely-deformed state of the union coupling, corps and bottom of thermal accumulator and the resource of work of these constructions is appraised. Thus admissible tension folds 225 МРа.

Determination Coefficient of Stress Concentration Using a Conformed Display on a Circle of a Single Radius

2021 ◽  
Vol 316 ◽  
pp. 928-935
Author(s):  
Alexander Shapoval ◽  
Iurii Savchenko ◽  
Oleg Markov
Keyword(s):  
Mathematical Model ◽  
Stress Concentration ◽  
Elastic Body ◽  
Defect Formation ◽  
Point Of View ◽  
Determination Coefficient ◽  
Arbitrary Loading ◽  
Deformed State ◽  
Single Radius

Developed a mathematical model, which makes it possible to optimize, from the point of view of defect formation, the parameters of stress concentration in a deformable elastic body of the materials being processed, destruction is considered as a method for creating defects at a submicroscopic level in various media. Getting expressions of conformal reflection of single circle on an arbitrary area, using a conformal reflection and transformation of Laplace, it is possible to design behavior of a tensely deformed state of solid at the arbitrary loading.

Experiment and simulation of friction coefficient of polyoxymethylene

2018 ◽  
Vol 70 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Xiaoshuang Xiong ◽  
Lin Hua ◽  
Xiaojin Wan ◽  
Can Yang ◽  
Chongyang Xie ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Friction Coefficient ◽  
Contact Pressure ◽  
Friction Force ◽  
Normal Load ◽  
Fe Model ◽  
Sliding Velocity ◽  
Experiment Data ◽  
Simulation Data ◽  
Content Type

Purpose The purposes of this paper include studying the friction coefficient of polyoxymethylene (POM) under a broad range of normal load and sliding velocity; developing a mathematical model of friction coefficient of POM under a broad range of normal loads and sliding velocities; and applying the model to dynamic finite element (FE) analysis of mechanical devices containing POM components. Design/methodology/approach Through pin-on-disc experiment, the friction coefficient of POM in different normal loads and sliding velocities is investigated; the average contact pressure is between 5 and 15 Mpa and the sliding velocity is from 0.05 to 0.9 m/s. A friction algorithm is developed and embedded in the FE model to simulate the friction of POM in different normal loads and sliding velocities. Findings The friction coefficient of POM against steel declines with the increase of normal loads when the contact pressure is between 5 and 15 Mpa. The friction coefficient of POM against steel increases markedly when the sliding velocity is between 0.05 and 0.15 m/s, it decreases sharply between 0.15-0.45 m/s and then it stabilizes at high sliding velocity between 0.45 and 0.9 m/s. The friction coefficient of POM in different working operations has a significant effect on contact stress and shear stress. The simulation data and experiment data of POM friction force fit very well; therefore, it can be concluded that the friction algorithm and FE model are accurate. Originality/value The friction coefficient of POM under a broad range of normal loads and sliding velocities is investigated. The friction coefficient model of POM is established as a function of normal loads and sliding velocities in the dry sliding condition. A friction algorithm is developed and embedded in the FE model of the friction of POM. The mathematical model of the friction coefficient accurately agrees with the experiment data, and simulation data and experiment data of the POM friction force fit very well.

Machining Profiling of the Working Rolls as a Way to Control Cross-Section of the Rolled Steel

2013 ◽  
Vol 762 ◽  
pp. 337-342 ◽  
Author(s):  
Aleksandr A. Astakhov ◽  
Dmitriy N. Dunaev ◽  
Igor Mazur
Keyword(s):  
Mathematical Model ◽  
Cross Section ◽  
Axial Direction ◽  
Correct Choice ◽  
Continuous Variable ◽  
Rolled Steel ◽  
Flatness Control ◽  
Deformed State ◽  
Contact Strip ◽  
Control And Management

ncrease of requirements to quality of the flat-rolled steel causes the appearance of new methods and improvement of the well-known approaches to improving the geometry of thin-gage rolled steels. On modern rolling mills, control and management of the strips cross-section is carried out by a profile and flatness control system (PFC). The main channel of the influence of such systems on the geometric parameters of the rolled steel is the axial shifting of S-shaped working rolls in CVC (Continuous Variable Crown) mills. The performance of the PFC is determined by the correct choice of the initial (machining) profile of the working rolls. The paper discusses the way to improve the methodology of grinding S-shaped working rolls by taking into account the stresses, arising in the zone of contact strip with rolls, the elastic deformation of roll system, thermal deformations, arising from the contact with the hot strip and wear of the working layer of the rolls during the campaign. The developed mathematical model of stress-deformed state allows you to determine the places with the highest stresses in the zone of contact strip with working rolls and adjust the initial profile of the rolls to ensure uniformity of extracts of a strip in width with regard to shifting rolls in the axial direction. The mathematical model of the thermal condition of S-shaped rolls, which allows to predict the change of the rolls thermal profile, gives the possibility to create the algorithm for the grinding of the working rolls in hot condition and increase the accuracy of performance of their machining profile.

scholarly journals MATHEMATICAL MODELING OF COLD PRESSING THE SHEET COMPOSITE

2020 ◽  
pp. 55-64
Author(s):  
B. M. Kumitskiy ◽  
N. A. Savrasova ◽  
V. N. Melkumov ◽  
Ye. S. Aralov
Keyword(s):  
Mathematical Model ◽  
Two Dimensions ◽  
Plastic Layer ◽  
Plasticity Condition ◽  
Interior Decoration ◽  
Linear Distribution ◽  
Cold Pressing ◽  
Approach Speed ◽  
Analytical Expressions ◽  
Construction Works

Statement of the problem. The article examines the problem of cold pressing, which is the most important technological component in the production of sheet composite, which is widely studied in the repair and construction works in the interior decoration of residential and industrial premises. The solution to this problem is carried out on the basis of a physical and mathematical model under the assumption that the rheological properties of the deformable medium correspond to the principles of ideal plasticity and a flat deformable state. Within the framework of the problem, in two dimensions of quasistatic compression between absolutely rigid parallel-approaching plates of a thin ideally plastic layer, the stress-strain state of a composite medium is studied. It is believed that in the absence of volumetric loads, the condition of incompressibility of the medium and the associated flow law is fulfilled. Based on the hypothesis of the linear distribution of tangential stresses over the thickness of the deformable layer, analytical expressions for the statistical and kinematic characteristics of the deformation are obtained, and the condition at the edges of the rough plates makes it possible to determine the coefficient of slip thorns, which makes it possible to control the pressing process.Results and conclusions. It was established that the components of the strain rate are directly proportional to the plate approach speed, and the normal stresses acting in the pressing direction are independent of the loading speed, decreasing in magnitude from the center to the periphery.Keywords: yield strength, pressing, plasticity condition, mathematical model.

scholarly journals Torque capacity of multidisc wet clutch with reference to friction occurrence on its spline connections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcin Bąk
Keyword(s):  
Mathematical Model ◽  
Contact Pressure ◽  
Experimental Research ◽  
Clamping Force ◽  
Pressure Plate ◽  
Wet Clutch ◽  
Torque Capacity ◽  
Friction Surfaces ◽  
Interest In Research ◽  
Specific Experiment

AbstractIn this article developed mathematical model that includes friction occurrence on spline connections is presented. The work also contains results of experimental research on torque capacity of multidisc wet clutch. These results are expressed as a function of contact pressure for different number of friction surfaces. Due to increased interest in research concerning multidisc wet clutches it is essential to determine impact of friction on fit connections on transmitted torque. Analytical calculations that include both known loss coefficient and assumed lack of friction on fit connections are compared to results of experiments. The paper contains detailed description of test stand and methodology of experiment. As a result of conducted tests it was found that correction coefficients known from literature are highly inaccurate. Measured values of torque indicate that transmitted torque reach significantly higher values. It was also revealed that after slippage appeared, the pressure plate usually moved in the direction of exerted clamping force, but movement in reversed direction also took place for some experiments. While movement corresponding to clamping force reached ca. 0.08 mm, in opposite direction amounted to 0.02 mm. Furthermore, studies presented that lapping of adjacent friction surfaces greatly affects differences between respective results obtained for a specific experiment.

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