A Reconstruction and Contact Analysis Method of Three-Dimensional Rough Surface Based on Ellipsoidal Asperity

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Yuqin Wen ◽  
Jinyuan Tang ◽  
Wei Zhou ◽  
Lin Li
Keyword(s):  
Rough Surface ◽  
Rough Surfaces ◽  
Minimum Mean Square Error ◽  
Three Dimensional ◽  
Contact Fatigue ◽  
Contact Analysis ◽  
Analysis Method ◽  
Surface Asperity ◽  
Surface Contact ◽  
Rough Surface Contact

Abstract The 3D rough surface modeling and contact analysis is a difficult problem in the study of rough surface contact. In this paper, a new method for reconstruction and contact analysis of asperities on 3D rough surfaces is proposed based on real rough surfaces. Watershed algorithm is used to segment and determine the area of asperities on the rough surface. According to the principle of minimum mean square error, ellipsoid fitting is carried out on asperities. Based on the elastic-plastic contact model of a single ellipsoidal asperity, a stable and efficient method for 3D rough surface contact analysis and calculation is proposed. Compared with existing calculating methods, the present method has the following characteristics: (1) the constructed surface asperity is closer to the real asperity in contact, and the calculation of asperity parameters has better stability under different sampling intervals and (2) the contact pressure, contact area, and other contact parameters of the 3D rough surface are calculated with high accuracy and efficiency, and the calculation convergence is desirable. The reconstruction and contact analysis method of the 3D rough surface asperity proposed in this paper provides a more accurate reconstruction and calculation method for the study of contact fatigue life and wear failure of rough surfaces.

A Comparative Study on Equivalent Modeling of Rough Surfaces Contact

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Xi Shi ◽  
Yunwu Zou
Keyword(s):  
Rough Surface ◽  
Rough Surfaces ◽  
Contact Analysis ◽  
Contact Forces ◽  
Sliding Contact ◽  
Contact Model ◽  
Surface Model ◽  
Normal Contact ◽  
Surface Contact ◽  
Rough Surface Contact

Greenwood and Tripp (GT model) have proposed that the contact analysis of two rough surfaces (two-rough-surface contact model) could be considered as an equivalent rough surface in contact with a rigid flat (single-rough-surface contact model). In this paper, by virtue of finite element method, the normal contact analysis was performed with two-rough-surface contact model and its equivalent single-rough-surface contact model, and it was verified that the resultant normal contact forces are in good agreement with each other for these two models, meanwhile the equivalent stress is a little bit lower for two-rough-surface model due to shoulder-to-shoulder contact. In contrast, the sliding contact analysis was also performed with these two models, respectively, and the results show a great disparity with each other in all contact parameters due to the strong plowing effects in two-rough-surface model. Therefore, this equivalence approach proposed by Greenwood and Tripp is only valid for normal contact of rough surfaces and not valid for sliding contact.

Lubrication of Rough Surfaces by a Boundary Film-Forming Viscosity Modifier Additive

2005 ◽  
Vol 127 (1) ◽  
pp. 223-229 ◽  
Author(s):  
R. P. Glovnea ◽  
A. V. Olver ◽  
H. A. Spikes
Keyword(s):  
Rough Surface ◽  
Rough Surfaces ◽  
Viscosity Index ◽  
Functionalized Polymers ◽  
Contact Conditions ◽  
Film Forming ◽  
Boundary Film ◽  
Surface Contact ◽  
Lubricated Contact ◽  
Rough Surface Contact

In previous work it was shown that some functionalized polymers used as viscosity index improvers are able to form thick boundary lubricating films. This behavior results from adsorption of the polymer on metal surfaces to form a layer of enhanced viscosity adjacent to the surface. In the current work the behavior of one such polymer in rough surface contact conditions is studied, using both model and real rough surfaces. It is found that the polymer is able to form a thick boundary film in rough surface contact, just as it does with smooth surfaces. It is also shown that the effect of this boundary film is to significantly reduce friction in rolling-sliding, rough surface, lubricated contact.

scholarly journals Principles of discrete-event modeling of physical processes during technical surfaces contact interaction

2021 ◽  
Vol 2094 (2) ◽  
pp. 022019
Author(s):  
A A Rachishkin
Keyword(s):  
Rough Surface ◽  
Data Storage ◽  
Contact Interaction ◽  
Rough Surfaces ◽  
Discrete Event ◽  
Three Dimensional ◽  
Advantages And Disadvantages ◽  
Event Modeling ◽  
Physical Experiments ◽  
Rough Surface Contact

Abstract The article discusses the advantages and disadvantages of computer modeling used in physical experiments field on rough surfaces contact interaction. Methods for constructing the software model are given. The description of a single irregularity in the form of revolution ellipsoid segment is presented and an algorithm for rough surface three-dimensional modeling based on it is proposed. Some assumptions made for generating surface topography do not significantly affect the simulation validity. Taking into account the individual parameters of each irregularity and the algorithm for their distribution make it possible to create inhomogeneous rough surfaces that are close to real ones relative to the physical experiments being carried out. The general principles of the software architecture and the data storage model of discrete-event modeling system of rough surface contact interaction are described. The developed software can be used for modeling the rough surfaces contact interaction, for researching of tribo-interface units’ parameters, predicting the characteristics of frictional interaction and tribotechnical tests computer simulation.

Study on Reconstruction of Fractal Rough Surfaces

2013 ◽  
Vol 278-280 ◽  
pp. 527-530
Author(s):  
Nan Zhang ◽  
Li Hua Wang ◽  
Yu Song He ◽  
Zi Lu
Keyword(s):  
Rough Surfaces ◽  
Three Dimensional ◽  
Computer Models ◽  
Contact Analysis ◽  
Solid Model ◽  
Fractal Surfaces ◽  
Contact Conductivity ◽  
Surface Contact

The geometric topography of the engineering surfaces play key roles in many issue of engineering and science including the analysis of friction, wear, lubrication, sealing and contact conductivity, especially microcosmic surface contact, thus the characterization of surface is one of the most important topics of tribology. Using the technology of CAD/CAE, a three-dimensional solid model of the fractal surfaces was established and meshed to provide the computer models for microcosmic contact analysis between two rough surfaces in this paper.

An FFT-Based Method for Rough Surface Contact

1997 ◽  
Vol 119 (3) ◽  
pp. 481-485 ◽  
Author(s):  
H. M. Stanley ◽  
T. Kato
Keyword(s):  
Rough Surface ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Exact Result ◽  
Elastic Contact ◽  
Two Dimensional ◽  
Surface Contact ◽  
Rigid Plane ◽  
Rough Surface Contact ◽  
Contact Pressures

Elastic contact between a rigid plane and a halfspace whose surface height is described by a bandwidth-limited Fourier series is considered. The surface normal displacements and contact pressures are found by a numerical technique that exploits the structure of the Fast Fourier Transform (FFT) and an exact result in linear elasticity. The multiscale nature of rough surface contact is implicit to the method, and features such as contact agglomeration and asperity interaction—a source of difficulty for asperity-based models—evolve naturally. Both two-dimensional (2-D) and three-dimensional (3-D) contact are handled with equal ease. Finally, the implementation is simple, compact, and fast.

scholarly journals Discrete Greenwood–Williamson Modeling of Rough Surface Contact Accounting for Three-Dimensional Sinusoidal Asperities and Asperity Interaction

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
S. Zhang ◽  
H. Song ◽  
S. Sandfeld ◽  
X. Liu ◽  
Y. G. Wei
Keyword(s):  
Analytical Solution ◽  
Rough Surface ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Contact Problems ◽  
Discrete Version ◽  
Successful Model ◽  
Surface Contact ◽  
Rough Surface Contact

Abstract The Greenwood–Williamson (GW) model has been one of the commonly used contact models to study rough surface contact problems during the past decades. While this has been a successful model, it still has a number of restrictions: (i) surface asperities are spheres; (ii) the overall deformation must be assumed to be small enough, such that there is no interaction between asperities, i.e., they are independent of each other; and (iii) asperity deformation remains elastic. This renders the GW model unrealistic in many situations. In the present work, we resolve above restrictions in a discrete version of the GW model: instead of spherical asperities, we assumed that the surface consists of three-dimensional sinusoidal asperities which appear more similar to asperities on a rough surface. For single asperity mechanical response, we propose a Hertz-like analytical solution for purely elastic deformation and a semi-analytical solution based on finite element method (FEM) for elastic–plastic deformation. The asperity interaction is accounted for by discretely utilizing a modified Boussinesq solution without consideration of asperity merger. It is seen that the asperity interaction effect is more than just the delay of contact as shown in the statistical model, it also contributes to the loss of linearity between the contact force and the contact area. Our model also shows that: for elastic contact, using spherical asperities results in a larger average contact pressure than using sinusoids; when plasticity is taken into account, using a sphere to represent asperities results in a softer response as compared with using sinusoids. It is also confirmed that sinusoidal asperities are a much better description than spheres, by comparison with fully resolved FEM simulation results for computer-generated rough surfaces.

Three-Dimensional Rough Surface Contact Model for Anisotropic Materials

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Ling He ◽  
Timothy C. Ovaert
Keyword(s):  
Rough Surface ◽  
Three Dimensional ◽  
Rigid Sphere ◽  
Reinforced Composites ◽  
Line Integral ◽  
Surface Contact ◽  
Gradient Technique ◽  
Anisotropic Elastic ◽  
Rough Surface Contact ◽  
Contact Parameters

By applying the line integral of Barnett–Lothe tensors on oblique planes, the three-dimensional rough surface contact problem for a semi-infinite anisotropic elastic half-plane in contact with a rough rigid sphere is formulated. The conjugate gradient technique of analytical continuation was employed to determine the contact parameters. The general solutions due to varying degrees of anisotropy and mechanical boundary conditions are obtained, and examples with fiber-reinforced composites are presented.

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