A Continuum Mechanics Model of Adhesive Contact Based on the Lennard-Jones Potential

2010 ◽  
Author(s):  
Z. Song ◽  
K. Komvopoulos
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Surface Displacement ◽  
Effective Elastic Modulus ◽  
Element Model ◽  
Adhesive Contact ◽  
Surface Interaction ◽  
Rigid Sphere ◽  
Adhesive Interaction ◽  
Lennard Jones

A continuum model of adhesive interaction between elastic surfaces is presented. Surface interaction between two elastic spheres is modeled by the Lennard-Jones (L-J) potential. The analysis is based on the equivalent system of a rigid sphere of reduced radius in close proximity with an elastic half-space of effective elastic modulus. The critical gap at the instant of the “jump-in” and “jump-out” contact instabilities is determined by an elastic solution of the half-space surface displacement. A finite element model, in which surface interaction is modeled by nonlinear springs of a prescribed force-displacement governed by the L-J potential, is also used to analyze adhesive surface interaction. The analytical model is validated by finite element results of the critical central gap at the instant of jumpin and jump-out instabilities for different values of the Tabor parameter.

Elasto-Plastic Coupled Temperature-Displacement Finite Element Analysis of Two-Dimensional Rolling-Sliding Contact With a Translating Heat Source

1991 ◽  
Vol 113 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. M. Kulkarni ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Plastic Material ◽  
Element Model ◽  
Rolling Contact ◽  
Two Dimensional ◽  
Element Analysis ◽  
Element Mesh ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The present paper, describes a transient translating elasto-plastic thermo-mechanical finite element model to study 2-D frictional rolling contact. Frictional two-dimensional contact is simulated by repeatedly translating a non-uniform thermo-mechanical distribution across the surface of an elasto-plastic half space. The half space is represented by a two dimensional finite element mesh with appropriate boundaries. Calculations are for an elastic-perfectly plastic material and the selected thermo-physical properties are assumed to be temperature independent. The paper presents temperature variations, stress and plastic strain distributions and deformations. Residual tensile stresses are observed. The magnitude and depth of these stresses depends on 1) the temperature gradients and 2) the magnitudes of the normal and tangential tractions.

A Finite Element Analysis of the Effect of Hardening Rules on the Indentation Test

1998 ◽  
Vol 120 (2) ◽  
pp. 143-148 ◽  
Author(s):  
N. Huber ◽  
Ch. Tsakmakis
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Half Space ◽  
Kinematic Hardening ◽  
Indentation Test ◽  
Rigid Sphere ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Hardening Rules

Using the Finite Element Method, an analysis is given of the indentation of an elasticplastic half-space by a rigid sphere. In particular, attention is focused on the effect of hardening rules on the material response. The materials considered are supposed to exhibit isotropic and kinematic hardening. Moreover, it is shown that the possibility of similar behavior due to effects of friction can be ruled out.

scholarly journals MODERN APPROACHES TO SOLVING THE CONTACT PROBLEM OF PRESSING A DOUBLESTAMP STAMP INTO AN ELASTIC HALF-SPACE

2021 ◽  
pp. 74-79
Author(s):  
Tetyana Zaytseva ◽  
Ivan Shmelov
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Contact Area ◽  
Software Package ◽  
Complex Shape ◽  
Element Model ◽  
Circular Ring ◽  
Elastic Half Space ◽  
Ansys Software ◽  
Java Language

The work is devoted to solving indentation problems into an elastic half-space of a cylindrical punch with a flat base by the vertical force. The force is aimed through the center of the base. The cross-section of the stamp is a doubly connected area bounded by two concentric lines. A concise review of methods for solving problems of analyzing the contact interaction of cylindrical dies with an elastic half-space is given. The solution of the problem in the form of decomposition by a small parameter is used when the equation of the edge curves depends on the same small parameter. To achieve it, in each approximation, the problem of indentation of a stamp with a doubly connected contact area in the form of a non-circular ring is reduced to a similar problem of indentation of a stamp with a contact area in the form of a circular ring. The software in the Java language has been developed for processing the analytical solution according to the obtained calculation formulas. With the help of the ANSYS software package, a finite element model of the contact interaction of an absolutely rigid stamp with an elastic half-space has been created. Numerical modeling was carried out using a licensed version of the program, free of charge. Several problems have been solved for square rings of different widths. The distribution of pressure under the stamp over different sections and the deepening of the stamp have been obtained. The pressure distribution graphs are plotted. When considering several test problems to assess the adequacy of the finite element model, the numerical results are compared with the results obtained analytically. The resulting model can analyze and predict loads, wear, and fracture of the contact area. The research prospects can include the solution of several problems of analysis of the stress-strain state of the interaction of dies of a complex shape with an elastic half-space, as well as groups of stamps of a complex shape, and the analysis of behavior models depending on the properties and characteristics of an elastic half-space. Keywords: contact problem, stamp, stress-strain state, modeling, JAVA language, finite element analysis, ANSYS software package.

Contribution of Surface Irregularities to Rolling Contact Plasticity in Bearing Steels

1995 ◽  
Vol 117 (4) ◽  
pp. 660-666 ◽  
Author(s):  
V. Gupta ◽  
G. T. Hahn ◽  
P. C. Bastias ◽  
C. A. Rubin
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Finite Element Model ◽  
Half Space ◽  
Kinematic Hardening ◽  
Constitutive Relations ◽  
Element Model ◽  
Bearing Steels ◽  
Deep Groove ◽  
Surface Irregularities

A “two-body” elasto-plastic finite element model of two-dimensional rolling and rolling-plus-sliding has been developed to treat the effect of surface irregularities. The model consists of a smooth cylinder in contact with a semi-infinite half-space that is either smooth or fitted with one of two irregularities: a 0.4 μm deep groove, or a 7 μm deep groove. The model incorporates elastic-linear-kinematic-hardening-plastic (ELKP) and nonlinear-kinematic-hardening-plastic (NLKP) material constitutive relations appropriate for hardened bearing steel and the 440C grade. The calculated contact pressure distribution is Hertzian for smooth body contact, and it displays intense, stationary, pressure spikes superposed on the Hertzian pressure for contact with the grooved and ridged surface. The results obtained for the 0.4 μm deep groove are consistent with those reported by Elsharkawy and Hamrock (1991) for an EHD lubricated contact. The effect of translating the counterface on the half space, as opposed to indenting the counterface on the half-space with no translation, is studied. The stress and strain values near the surface are found to be similar for the two cases, whereas they are significantly different in the subsurface. Efforts have been made to identify the material constitutive relations which best describe the deformation characteristics of the bearing steels in the initial few cycles. ELKP material constitutive relations produce less net plastic deformation in the initial stages, for a given stress, than seen in experiments. NLKP model produces more plasticity than the ELKP model and shows promise for treating the net distortions in the early stages. Artificial indents were inserted on the running track of the cylindrical rolling elements and profilometer measurements of these indents were made, before and after rolling. These preliminary measurements show that substantial plastic deformation takes place in the process of rolling. The deformations of the groove calculated with the finite element model are compared to those measured experimentally.

Dynamic Finite Element Analysis of an Elastic-Plastic Half-Space Indented by a Rigid Sphere

2010 ◽  
Author(s):  
A. Lee ◽  
K. Komvopoulos
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Equivalent Plastic Strain ◽  
Dynamic Contact ◽  
Rigid Sphere ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Wide Range ◽  
Deformation Velocity ◽  
Elastic Plastic Materials

Dynamic indentation of an elastic-plastic half-space by a rigid sphere was studied with the finite element method. A parametric analysis was performed to examine the effects of indentation velocity and yield strength of the half-space material on dynamic contact deformation. Velocity effects are discussed in the context of simulation results of global and local contact parameters, such as mean contact pressure, contact area, and equivalent plastic strain. The evolution of deformation as the material response transitions from elastic to fully-plastic deformation during dynamic contact is interpreted in light of numerical results. This study elucidates the effect of dynamic contact loading on the deformation behavior of elastic-plastic materials for a wide range of length scales where a continuum mechanics description holds.

Impact of a Rigid Sphere on an Elastic Homogeneous Half-Space

2005 ◽  
Vol 127 (2) ◽  
pp. 325-330 ◽  
Author(s):  
J. Yang ◽  
K. Komvopoulos
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Contact Pressure ◽  
Contact Area ◽  
Real Contact Area ◽  
Rigid Sphere ◽  
Small Surface ◽  
Real Contact ◽  
Homogeneous Half Space ◽  
The Mean

The impact of a rigid sphere moving at constant velocity on elastic homogeneous half-space was analyzed by the finite element method. Frictionless dynamic contact was modeled with special contact elements at the half-space surface. A dimensionless parameter, β, was introduced to study the effect of wave propagation on the deformation behavior. For small surface interference (β⩽1), the front of the faster propagating dilatational waves extends up to the contact edge, the real contact area is equal to the truncated area, and the contact pressure distribution is uniform. However, for large surface interference (β>1), the dilatation wave front extends beyond the contact edge, the real contact area is less than the truncated area, and the contact pressure exhibits a Hertzian-like distribution. The mean contact pressure increases abruptly at the instant of initial contact, remains constant for β⩽1, and increases gradually for β>1. Based on finite element results for the subsurface stress, strain, and velocity fields, a simple theoretical model that yields approximate closed-form relationships for the mean contact pressure and kinetic and strain energies of the half-space was derived for small surface interference (β⩽1), and its validity was confirmed by favorable comparisons with finite element results.

Modeling of Phases Adhesion in Composite Materials Based on Spring Finite Element with Zero Length

2018 ◽  
Vol 780 ◽  
pp. 3-9 ◽  
Author(s):  
Alexander Pavlovich Sokolov ◽  
Vitaliy Nikolaevich Schetinin
Keyword(s):  
Finite Element ◽  
Elastic Properties ◽  
Three Dimensional ◽  
Adhesive Layer ◽  
Variable Stiffness ◽  
Element Model ◽  
Adhesive Contact ◽  
Reinforced Composites ◽  
New Approach ◽  
Spring Element

A new numerical method for homogenization of elastic properties of dispersedly-reinforced composites was presented. The method takes into account special model of adhesive contact. Homogenization of properties was performed by averaging the solutions of boundary value problems on representative volume cell (RVC) using the finite element method (FEM). A new approach of calculation of components of effective tensor of elastic moduli was proposed. A heterogeneous finite element model with elements of two types was built: three-dimensional tetrahedron elements for every phases and spring element with zero-length for adhesion layer with zero-thickness. The results of homogenization of elastic properties of dispersedly-reinforced composites with variable stiffness of the adhesive layer between phases were obtained and analyzed. The homogenization results were compared with the available experimental data.

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