scholarly journals Investigation of Thermostressed State of Coating Formation at Electric Contact Surfacing of “Shaft” Type Parts

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Olena V. Berezshnaya ◽  
Eduard P. Gribkov ◽  
Valeriy D. Kuznetsov
Keyword(s):  
Finite Thickness ◽  
Asymmetry Factor ◽  
Electric Contact ◽  
Technological Capabilities ◽  
Deformation Degree ◽  
Compact Material ◽  
Thermostressed State ◽  
Coating Formation ◽  
Difference Form ◽  
The Mathematical Model

The forming of coating at electric contact surfacing is considered. The mathematical model of the coating formation is developed. The method of numerical recurrent solution of the finite-difference form of static equilibrium conditions of the selected elementary volume of coating is used. This model considers distribution of thermal properties and geometric parameters along the thermal deformation zone during the process of electric contact surfacing by compact material. It is found that the change of value of speed asymmetry factor leads to increasing of the friction coefficient in zone of surfacing. This provides the forming of the coating of higher quality. The limitation of the technological capabilities of equipment for electric contact surfacing is related to the size of recoverable parts and application of high electromechanical powers. The regulation of the speed asymmetry factor allows for expanding the technological capabilities of equipment for electric contact surfacing. The nomograms for determination of the stress on the roller electrode and the finite thickness of the coating as the function of the initial thickness of the compact material and the deformation degree are shown.

scholarly journals The Finite Element Modulation of Thermostressed State of Coating Formation at Electric Contact Surfacing of “Shaft” Type Parts

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Olena V. Berezshnaya ◽  
Eduard P. Gribkov ◽  
Pavlo V. Borovik ◽  
Valeriy D. Kassov
Keyword(s):  
Finite Element ◽  
Current Pulse ◽  
Thermal Deformation ◽  
Asymmetry Factor ◽  
Electric Contact ◽  
Thermostressed State ◽  
Coating Formation ◽  
Thermal Influence ◽  
Operating Regimes

The finite element modulation of forming of coating at electric contact surfacing is provided. This model considers distribution of thermal properties and geometric parameters along the thermal deformation zone during the process of electric contact surfacing by tapes. It is found that the change of the value of the speed asymmetry factor leads to increasing of the friction coefficient in the zone of surfacing which is caused by the increasing of the tangential contact stresses in the zone of contact of the electrode tape with the surface of the part. This leads to the forming of the coating with higher adhesion strength, and thereby the higher quality of the restored part under the lower operating regimes such as current pulse, force of the roller electrode, and duration of the current pulse is achieved. Mentioned above allows to decrease the thermal influence on the structure of the material.

Mathematical Model of Hot Deformation Resistance of X120 Pipeline Steel

2012 ◽  
Vol 538-541 ◽  
pp. 1724-1731
Author(s):  
Hong Wei Zheng ◽  
Di Tang ◽  
Hui Bin Wu ◽  
Liu Yang
Keyword(s):  
Mathematical Model ◽  
Deformation Rate ◽  
Deformation Temperature ◽  
Pipeline Steel ◽  
Deformation Resistance ◽  
Effect Of Temperature ◽  
Temperature Deformation ◽  
Test Machine ◽  
Deformation Degree ◽  
The Mathematical Model

The high-temperature deformation resistance of X120 pipeline steel was studied under different deformation temperature and different deformation rate through the hot compression test on the Gleeble-3500 thermal/mechanics simulation test machine. The influence of deformation degree, deformation temperature and deformation rate on deformation resistance was thoroughly investigated. The deformation resistance of X120 pipeline steel increased slowly when deformation degree was higher than 0.2. With the increase of deformation temperature, the work-hardening effect was weakened, so the deformation resistance decreased. And the deformation rate had dual influences on the deformation resistance, including the effect of temperature and time. Based on the experiment data, the parameters in the mathematical model were regressed by using SPSS (Statistic Package for Social Science), and the mathematical model of the deformation resistance of X120 pipeline steel was established finally. Through the regression analysis, the model had been proved to have great matching precision.

scholarly journals Wavelet Approach for Vibration Analysis of Fast Moving Load on a Viscoelastic Medium

2010 ◽  
Vol 17 (4-5) ◽  
pp. 461-472 ◽  
Author(s):  
Piotr Koziol ◽  
Cristinel Mares
Keyword(s):  
Boundary Conditions ◽  
Fast Moving ◽  
Moving Load ◽  
Finite Thickness ◽  
Constant Load ◽  
Order Of Accuracy ◽  
Wavelet Approximation ◽  
Complex Models ◽  
The Mathematical Model ◽  
Different Order

This paper analyses theoretically the response of a solid for fast moving trains using models related to real situations: a load moving in a tunnel and a load moving on a surface. The mathematical model is described by Navier's elastodynamic equation of motion for the soil and Euler-Bernoulli equation for the beam with appropriate boundary conditions. Two modelling approaches are investigated: the model with half space under the beam and the model with finite thickness of supporting medium. The problem of singularities for displacements calculation is discussed in relation with boundary conditions and types of considered loads: harmonic and constant, point and distributed moving loads. The analysis in frequency-time and frequency-velocity domains is presented and discussed with regard to critical velocities.A wavelet approximation method based on application of coiflet filters is used for the derivation of displacements in physical domain. A new, modified filter is used in numerical calculations allowing to alleviate numerical difficulties related to the form of approximating sequences based on classical filters, formulated in previous publications. The effectiveness of the coiflet approach is discussed for filter coefficients with different order of accuracy. This methodology is very efficient for the analysis in the range of relatively high and low load frequencies (treated as an approximation of a constant load) which are especially important for the analysis of vibrations generated by trains moving with velocities near critical values.Results of numerical simulations are presented, demonstrating their utility for modelling and preliminary analysis of complex models.

Establishment of Flow Stress Model of EW75 Alloy

2013 ◽  
Vol 423-426 ◽  
pp. 241-246
Author(s):  
Ming Long Ma ◽  
Kui Zhang
Keyword(s):  
Mathematical Model ◽  
Flow Stress ◽  
Magnesium Alloy ◽  
Strain Rate ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Stress Strain ◽  
Deformation Degree ◽  
Maximum Deformation ◽  
The Mathematical Model

The behavior evolvement of Mg-7.22Gd-4.84Y-1.26Nd-0.58Zr (EW75) magnesium alloy during the hot deformation process was discussed. The flow stress behavior of magnesium alloy over the strain rate range 0.002s-1to 2s-1and the temperature range 623K to 773K had been researched on Gleeble-1500D hot simulator under the maximum deformation degree 60%. A mathematical model was established to predict the stress-strain curves of this alloy during deformation. The experimental results showed that the stress-strain curves were obviously affected by the strain rates and deformation temperatures. The mathematical model could predict the stress-strain curves when the strain rates were under 0.2-1, but there was significant error in some of stress-strain curves when the strain-rate was 2-1by the reason of deformation temperature rising.

A Model of a Combined Film Deposition and Ion Bombardment for Coatings Formation

1988 ◽  
Vol 128 ◽  
Author(s):  
Z. A. Iskanderova ◽  
T. D. Radjabov ◽  
R. Yu. Leiderman ◽  
F. K. Tukfatullin
Keyword(s):  
Mathematical Model ◽  
Ion Implantation ◽  
Ion Bombardment ◽  
Film Deposition ◽  
High Dose ◽  
Concentration Profiles ◽  
Coating Formation ◽  
The Mathematical Model

ABSTRACTThe mathematical model of a combined film deposition and and high dose ion implantation for coating formation has been developed. Calculations of concentration profiles of implanted element in the film and substrate depending on different parameters of the model have been carried out.

Mathematical Model and Program Development for the Efficient Process Conditions Determination during FeC0.15Cr12Ni2 Steel Diamond Smoothing

2016 ◽  
Vol 684 ◽  
pp. 477-482 ◽  
Author(s):  
Aleksei Nicolaevich Shvetcov ◽  
Dmitrii Leonidovich Skuratov
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Surface Layer ◽  
Program Development ◽  
Synthetic Diamond ◽  
Process Conditions ◽  
Deformation Degree ◽  
Efficient Process ◽  
The Mathematical Model

In this paper the mathematical model and the program based on this model for efficient process conditions during a diamond smoothing is introduced. The mathematical model has been tested with heatproof martensite category steel FeC0.15Cr12Ni2 by the synthetic diamond DSB-1 using as a smoothing tool. The mathematical model takes into account plastic deformation degree which could have both smoothing and reinforcing nature. Through the smoothing conditions the surface has a microroughnesses crumpling but reinforcing conditions involve also surface layer microhardness increasing.

The Mathematical Model of the Relation among the Resistance, the Distortion Temperature and the Rate of the Steel in the Plastic Deformation

2012 ◽  
Vol 502 ◽  
pp. 184-188
Author(s):  
Hong Li ◽  
Xiao Lin You
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Basic Theory ◽  
Deformation Resistance ◽  
Deformation Degree ◽  
Plastic Processing ◽  
Hardening Curve ◽  
Fundamental Equations ◽  
The Mathematical Model

the hardening curve of the steel in the plastic deformation only considers the influence of the deformation degree on the resistance. This paper, according to the basic theory of plastic processing, proposes out the respective relation between the deformation resistance and the deformation degree, the temperature, as well as the rate. This paper gets the curves of these relations by experiments, summarizes the fundamental equations by simulation and finally deduces the plastic conditional equations relating to the material performance----the tensile strength.

Mathematical Modeling of Pulsed Electro Contact Sintering of Carbide Powder Composition

2014 ◽  
Vol 1040 ◽  
pp. 495-499 ◽  
Author(s):  
Svetlana N. Sorokova ◽  
Anna G. Knyazeva ◽  
Alexsey Pobol ◽  
George Goranskyi
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Carbide Powder ◽  
Electric Contact ◽  
Powder Composition ◽  
The Mathematical Model

The mathematical model of pulsed electric contact sintering of carbide powder compositions are suggested and investigated. The distributions of temperature, density and thickness of the rate during sintering are determined

The Coupling of Conduction With Laminar Natural Convection From a Vertical Flat Plate With Arbitrary Surface Heating

1970 ◽  
Vol 92 (3) ◽  
pp. 528-535 ◽  
Author(s):  
A. E. Zinnes
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Flat Plate ◽  
Finite Thickness ◽  
Heat Conducting ◽  
Constant Property ◽  
Difference Form ◽  
Laminar Natural Convection ◽  
Degree Of Coupling ◽  
Experimental Corroboration

A method has been developed for coupling conduction in a solid with natural convection in a surrounding fluid. The problem investigated is that of steady, constant-property, two-dimensional, laminar natural convection from a vertical, heat-conducting flat plate of finite thickness with an arbitrary heating distribution in its surface. Using this method it is possible to predict the variation of temperature in the plate and the velocity and temperature profiles in the boundary layer as a function of the heating distribution and the thermal properties of the plate and fluid. The equations for conduction in the plate and convection in the boundary layer are written in finite difference form, coupled through the common heat flux at the plate-fluid interface, and solved numerically by an iterative technique. Experimental corroboration of the numerical results is provided by measuring temperatures, both with thermocouples and a laser holographic interferometer, along ceramic and glass plates heated by thin film resistance heating elements vacuum deposited on their surface. The results indicate that the degree of coupling between conduction in the plate and natural convection in the fluid is greatly influenced by the plate-fluid conductivity ratio.

Double-Diffusive Natural Convection in an Enclosure Having Finite Thickness Walls

2010 ◽  
Author(s):  
Geniy V. Kuznetsov ◽  
Mikhail A. Sheremet
Keyword(s):  
Mass Transfer ◽  
Rayleigh Number ◽  
Heat And Mass Transfer ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Local Heat ◽  
Vorticity Vector ◽  
Implicit Finite Difference ◽  
The Mathematical Model ◽  
Buoyancy Ratio

This study is a computational work devoted to mathematical simulation of three-dimensional conjugate heat and mass transfer in an enclosure having finite thickness walls with local heat and mass sources. The mathematical model written in dimensionless variables “vorticity vector – vector potential functions – temperature – concentration” has been solved using an iterative implicit finite-difference method. The heat and mass transfer characteristics of the three-dimensional enclosure have been analyzed using the streamlines, temperature and concentration fields. Main attention was paid to the effects of the Rayleigh number, buoyancy ratio and transient factor on the heat and mass transfer modes. The correlations describing the dependences of average Nusselt and Sherwood numbers on the thermal Rayleigh number have been obtained.

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