Real single grain grinding FEM simulation for case-hardened steel based on equivalent contact area analysis

2021 ◽  
pp. 1-24
Author(s):  
Flavia Lerra ◽  
Erica Liverani ◽  
Enrico Landi ◽  
Alessandro Fortunato
Keyword(s):  
Contact Area ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Hardened Steel ◽  
Simulation Software ◽  
Real Contact Area ◽  
Depth Of Cut ◽  
Production Chain ◽  
Percentage Difference ◽  
Single Grain

Abstract Grinding is an indispensable phase in the gear production chain as it allows very stringent requirements characteristic of the automotive sector to be satisfied. The main goal of this finishing process is to ensure compliance with the surface integrity and dimensional tolerance specifications of the product. A single-grain grinding FEM model has been implemented to predict grinding load values based on real grain geometry using a set of Johnson & Cook coefficients able to represent the flow stress curve of a typical gear case-hardened steel 27MnCr5. Grain geometry acquired through computed tomography was imported into three-dimensional process simulation software DEFORM-3D. As the use of real grain geometry leads to time-consuming simulations, an equivalent defined geometry grain was implemented to compare cutting behavior and calculate maximum force values through real contact area analysis under the same process parameters. Calculated loads were subsequently compared with experimental results, showing good agreement with a maximum percentage difference less than 13% for two different grain geometries. Grinding force measurements were performed in a single-grain configuration on a CNC surface grinding machine adopting a wheel speed of 384 rad/s, feed rate of 8.6 mm/s and a depth of cut of 0.1 mm.

Finite-Element Analysis of Rotor in the Rubber Continuous Plasticator

2013 ◽  
Vol 561 ◽  
pp. 174-177
Author(s):  
Ping Fu ◽  
Hong Lei Zhang ◽  
Chuan Sheng Wang
Keyword(s):  
Finite Element Analysis ◽  
High Efficiency ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Simulation Software ◽  
Rubber Compound ◽  
Three Dimensional Flow ◽  
Element Analysis ◽  
Simulation Calculation ◽  
Optimizing Design

The three-dimensional flow fields produced by the modular dual-rotor of rubber continuous plasticator were numerically simulated and analyzed by using ADINA, the FEM simulation software. So the velocity field distribution of each rotor element was shown by the simulations. Through the analysis, the double rotors rotated inward had high efficiency of pumping and plasticization. The rubber compound was subjected to the strong shearing action; squeezing action and stretch effect in the rubber plasticate process. The simulation calculation had great significance for the rotor optimizing design.

Unloading Process in Elastic-Plastic Contact of a Rough Surface With a Flat

2008 ◽  
Author(s):  
A. Sepehri ◽  
K. Farhang
Keyword(s):  
Finite Element ◽  
Rough Surface ◽  
Contact Force ◽  
Contact Area ◽  
Three Dimensional ◽  
Integral Form ◽  
Real Contact Area ◽  
Elastic Plastic ◽  
Real Contact ◽  
Approximate Equations

Three dimensional elastic-plastic contact of a nominally flat rough surface and a flat is considered. The asperity level Finite Element based constitutive equations relating contact force and real contact area to the interference is used. The statistical summation of asperity interaction during unloading phase is derived in integral form. Approximate equations are found that describe in closed form contact load as a function of mean plane separation during unloading. The approximate equations provide accuracy to within 6 percent for the unload phase of the contact force.

On the Mechanism of Contact Between Metal Surfaces: Part 2—The Real Area and the Number of the Contact Points

1968 ◽  
Vol 90 (1) ◽  
pp. 81-88 ◽  
Author(s):  
T. Tsukizoe ◽  
T. Hisakado
Keyword(s):  
Contact Area ◽  
Three Dimensional ◽  
Real Contact Area ◽  
Load Range ◽  
The Real ◽  
Real Contact ◽  
Contact Points ◽  
Theoretical Analyses ◽  
Total Contact Area ◽  
Real Area

Assuming that the distribution curve obtained from the profile curve of the surface has a normal distribution, the relation between the real contact area and the separation is obtained theoretically in the case of ideal plastic flow of the microcontacts. If the asperities are cones of the same angle which depends on the surface roughness, the three-dimensional number and the distribution of the radii of contact points are also deduced theoretically. The results of the theoretical analyses are compared with the experimental results for the real contact areas and the numbers of the contact points. Results show that over the wide load range the average radii of contact points are almost constant; consequently, the total contact area is increased mainly owing to the increase in the number of the contact points.

scholarly journals Tire–Road Contact Area on Asphalt Concrete Pavement and Its Relationship with the Skid Resistance

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 615 ◽  
Author(s):  
Di Yun ◽  
Liqun Hu ◽  
Cheng Tang
Keyword(s):  
Traffic Safety ◽  
Contact Area ◽  
Three Dimensional ◽  
Real Contact Area ◽  
Skid Resistance ◽  
Test Machine ◽  
Multi Scale ◽  
Asphalt Concrete Pavement ◽  
The Impact ◽  
Scale Roughness

Sufficient pavement skid resistance is one of the essential factors to ensure traffic safety. The real contact area (Ar) between the tire and road is significant for understanding and improving the skid resistance performance. In this study, the tire–road contact area is measured by squeezing a smooth underside-dyed rubber block into the specimens, using a self-designed fixture mounted on the universal test machine. The three-dimensional (3D) printing technology is used to separate the specimens with multi-scale roughness. Surface texture on 29 AC pavements is obtained by a 3D scanner and qualified by the root-mean-square surface height (Sq), to investigate the impact of pavement texture on the Ar. The skid resistance on 23 AC road sections is measured using the T2GO system, and the pavement texture is recorded, to discuss the influence of the Ar on the skid resistance. The results indicate that the multi-scale roughness rarely affects the measured contact area once the concerned wavelength is less than 0.6 mm. The Ar decreases with the Sq following a power function but has weak correlation with the friction coefficient. This study could provide an in-depth understanding of the tire–road contact and lays a foundation for optimizing the contact-related pavement performance.

An FFT Deterministic Simulation of Elastic Rough Surfaces in Three-Dimensional Contact and Model Analysis

2009 ◽  
Author(s):  
Robert L. Jackson ◽  
Itzhak Green
Keyword(s):  
Contact Area ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Three Dimensional ◽  
Real Contact Area ◽  
Real Contact ◽  
Contact Models ◽  
Surface Profiles ◽  
Rough Surface Contact ◽  
Mathematical Foundations

For practicing engineers in industry it is important to have closed-form, easy to use equations that can be used to predict the real contact area, and relate it to friction, wear, adhesion, and electrical and thermal contact resistance. There are quite a few such models in the literature, but their agreement or their effectiveness has not been determined. This work will use several measured surface profiles to make predictions of contact area and contact force from many elastic contact models and compare them to a deterministic FFT based rough surface contact model. The results show that several of the models show good quantitative and qualitative agreement despite having very different mathematical foundations.

Three-Dimensional Contact Analysis of Elastic-Plastic Layered Media With Fractal Surface Topographies

2000 ◽  
Vol 123 (3) ◽  
pp. 632-640 ◽  
Author(s):  
K. Komvopoulos ◽  
N. Ye
Keyword(s):  
Contact Area ◽  
Three Dimensional ◽  
Homogeneous Medium ◽  
Real Contact Area ◽  
Rigid Sphere ◽  
Real Surface ◽  
Elastic Plastic ◽  
Real Contact ◽  
Fractal Parameters ◽  
Surface Topographies

Three-dimensional rough surfaces were generated using a modified two-variable Weierstrass-Mandelbrot function with fractal parameters determined from real surface images. The number and size of truncated asperities were assumed to follow power-law relations. A finite element model of a rigid sphere in normal contact with a semi-infinite elastic-plastic homogeneous medium was used to obtain a constitutive relation between the mean contact pressure, real contact area, and corresponding representative strain. The contact model was extended to layered media by modifying the constitutive equation of the homogeneous medium to include the effects of the mechanical properties of the layer and substrate materials and the layer thickness. Finite element simulations of an elastic-plastic layered medium indented by a rigid sphere validated the correctness of the modified contact model. Numerical results for the contact load and real contact area are presented for real surface topographies resembling those of magnetic recording heads and smooth rigid disks. The model yields insight into the evolution of elastic, elastic-plastic, and fully plastic deformation at the contact interface in terms of the maximum local surface interference. The dependence of the contact load and real contact area on the fractal parameters and the carbon overcoat thickness is interpreted in light of simulation results obtained for a tri-pad picoslider in contact with a smooth thin-film hard disk.

Effect of normal load on the frictional and wear behaviour of carbon fiber in tow-on-tool contact during three-dimensional weaving process

2020 ◽  
pp. 152808372094461
Author(s):  
Ning Wu ◽  
Ximing Xie ◽  
Jie Yang ◽  
Yajie Feng ◽  
Yanan Jiao ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Contact Area ◽  
Normal Load ◽  
Three Dimensional ◽  
Hertzian Contact ◽  
Wear Behaviour ◽  
Real Contact Area ◽  
The Real ◽  
Real Contact ◽  
Fracture Damage

The effect of normal load on the frictional and wear behaviour of carbon fiber is investigated by simulating the tow-on-tool friction relevant to the beating-up motion of three-dimensional (3 D) weaving process. The true number of contact filaments over a range of normal loads is calculated by characterizing the cross-section parameters of carbon tow. The real contact area is calculated on the basis of the filaments amount by Hertzian contact model. The friction force values obtained from multiplying the real contact area with shear strength are closely with the measured results. The coefficient of friction increases with the increase of normal loads. When the normal load is 250, 400 and 600 mN, the tensile loss rate of the carbon tow after friction test is 6.3%, 23.2% and 42.4% respectively. The filaments reveal multiple fracture damage patterns which are caused by stretching, shearing and compression during the weaving process.

An Analytical Thermodynamic Approach to Friction of Rubber on Ice

2012 ◽  
Vol 40 (2) ◽  
pp. 124-150
Author(s):  
Klaus Wiese ◽  
Thiemo M. Kessel ◽  
Reinhard Mundl ◽  
Burkhard Wies
Keyword(s):  
Coefficient Of Friction ◽  
Liquid Layer ◽  
Contact Area ◽  
Leading Edge ◽  
Viscous Friction ◽  
Analytical Approximation ◽  
Real Contact Area ◽  
Length Scales ◽  
Real Contact ◽  
Ice Surface

ABSTRACT The presented investigation is motivated by the need for performance improvement in winter tires, based on the idea of innovative “functional” surfaces. Current tread design features focus on macroscopic length scales. The potential of microscopic surface effects for friction on wintery roads has not been considered extensively yet. We limit our considerations to length scales for which rubber is rough, in contrast to a perfectly smooth ice surface. Therefore we assume that the only source of frictional forces is the viscosity of a sheared intermediate thin liquid layer of melted ice. Rubber hysteresis and adhesion effects are considered to be negligible. The height of the liquid layer is driven by an equilibrium between the heat built up by viscous friction, energy consumption for phase transition between ice and water, and heat flow into the cold underlying ice. In addition, the microscopic “squeeze-out” phenomena of melted water resulting from rubber asperities are also taken into consideration. The size and microscopic real contact area of these asperities are derived from roughness parameters of the free rubber surface using Greenwood-Williamson contact theory and compared with the measured real contact area. The derived one-dimensional differential equation for the height of an averaged liquid layer is solved for stationary sliding by a piecewise analytical approximation. The frictional shear forces are deduced and integrated over the whole macroscopic contact area to result in a global coefficient of friction. The boundary condition at the leading edge of the contact area is prescribed by the height of a “quasi-liquid layer,” which already exists on the “free” ice surface. It turns out that this approach meets the measured coefficient of friction in the laboratory. More precisely, the calculated dependencies of the friction coefficient on ice temperature, sliding speed, and contact pressure are confirmed by measurements of a simple rubber block sample on artificial ice in the laboratory.

THREE DIMENSIONAL FEM SIMULATION OF TITANIUM HOLLOW MONOLITHIC STRUCTURE PROCESS BASED ON VISCO--PLASTIC CONSTITUTIVE

2010 ◽  
Vol 46 (4) ◽  
pp. 396-403
Author(s):  
Bing ZHAO ◽  
Zhiqiang LI ◽  
Xiuquan HAN ◽  
Jinhua LIAO ◽  
Hongliang HOU ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Fem Simulation ◽  
Monolithic Structure

Thermomechanical Coupling of a Hyper-viscoelastic Truck Tire and a Pavement Layer and its Impact on Three-dimensional Contact Stresses

2021 ◽  
pp. 036119812110171
Author(s):  
Angeli Jayme ◽  
Imad L. Al-Qadi
Keyword(s):  
Contact Stress ◽  
Contact Area ◽  
Three Dimensional ◽  
Interaction Model ◽  
Rolling Resistance ◽  
Contact Stresses ◽  
Thermomechanical Coupling ◽  
Temperature Profiles ◽  
Near Surface ◽  
Truck Tire

A thermomechanical coupling between a hyper-viscoelastic tire and a representative pavement layer was conducted to assess the effect of various temperature profiles on the mechanical behavior of a rolling truck tire. The two deformable bodies, namely the tire and pavement layer, were subjected to steady-state-uniform and non-uniform temperature profiles to identify the significance of considering temperature as a variable in contact-stress prediction. A myriad of ambient, internal air, and pavement-surface conditions were simulated, along with combinations of applied tire load, tire-inflation pressure, and traveling speed. Analogous to winter, the low temperature profiles induced a smaller tire-pavement contact area that resulted in stress localization. On the other hand, under high temperature conditions during the summer, higher tire deformation resulted in lower contact-stress magnitudes owing to an increase in the tire-pavement contact area. In both conditions, vertical and longitudinal contact stresses are impacted, while transverse contact stresses are relatively less affected. This behavior, however, may change under a non-free-rolling condition, such as braking, accelerating, and cornering. By incorporating temperature into the tire-pavement interaction model, changes in the magnitude and distribution of the three-dimensional contact stresses were manifested. This would have a direct implication on the rolling resistance and near-surface behavior of flexible pavements.

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