Influence of the Tabor Parameter on the Roughness-Induced Adhesion Hysteresis

2012 ◽  
Vol 157-158 ◽  
pp. 1233-1237
Author(s):  
Le Feng Wang ◽  
Wei Bin Rong ◽  
Bing Shao ◽  
Li Ning Sun
Keyword(s):  
Rough Surface ◽  
Rough Surfaces ◽  
Adhesive Contact ◽  
Contact Model ◽  
Dissipation Energy ◽  
Dugdale Model ◽  
Relationship Of ◽  
Special Case ◽  
Tabor Parameter

Influence of the Tabor parameter on the roughness-induced adhesion hysteresis was investigated. To achieve this, the adhesive contact model of single asperities was considered by incorporating the Maugis-dugdale model and its corresponding extension firstly. Further more, the load-approach relationship of adhesive contact between a rough surface and a flat was analyzed. The dissipation energy during a load and unload cycle is derived for general values of the Tabor parameter. It was found that the adhesion hysteresis becomes weaker gradually with the increase of the adhesion parameter, and it becomes stronger with the decrease of the Tabor parameter at the same adhesion parameter. The adhesion hysteresis for a special case that rough surfaces with DMT(Deryagin-Muller-Toporov)-type asperities is also discussed.

Analysis of Plastic Strain between Substrate and Micro-Cantilever under Different Deformation Characteristics

2013 ◽  
Vol 477-478 ◽  
pp. 21-24
Author(s):  
Hui Kai Gao ◽  
Jian Meng Huang
Keyword(s):  
Plastic Strain ◽  
Rough Surface ◽  
Three Dimensional ◽  
Equivalent Plastic Strain ◽  
Adhesive Contact ◽  
Contact Model ◽  
Deformation Characteristics ◽  
Element Analysis ◽  
Flat Substrate ◽  
Micro Cantilever

The contact between substrate and micro-cantilever simplified as an ideal flat substrate contact with a micro-cantilever rough surface. A three-dimensional adhesive contact model was established on isotropic rough surfaces exhibiting fractal behavior, and the equivalent plastic strain was discussed using the finite element analysis. The maximum equivalent plastic strain and its depth were presented with the different paths of rough solid when loading. The result show that the equivalent plastic strain versus different depth which at different locations showed different laws, in the top area of the asperities versus different depth, the maximum equivalent plastic strain occurs in the subsurface range about 0.5μm from the surface or on the surface. In addition, with different deformation characteristics, the degree of the equivalent plastic strain was different.. The contact model between micro-cantilever rough surface and flat substrate will lay a foundation to further research on the substance of the process of friction and wear.

Adhesive Contact on Randomly Rough Surfaces Based on the Double-Hertz Model

2013 ◽  
Vol 81 (5) ◽  
Author(s):  
Wei Zhang ◽  
Fan Jin ◽  
Sulin Zhang ◽  
Xu Guo
Keyword(s):  
Energy Dissipation ◽  
Rough Surface ◽  
Cohesive Zone Model ◽  
Adhesive Contact ◽  
Radius Of Curvature ◽  
Zone Model ◽  
Asperity Contact ◽  
Dissipation Energy ◽  
Hertz Model ◽  
Flat Surfaces

A cohesive zone model for rough surface adhesion is established by combining the double-Hertz model (Greenwood, J. A., and Johnson, K. L., 1998, “An Alternative to the Maugis Model of Adhesion Between Elastic Spheres,” J. Phys. D: Appl. Phys., 31, pp. 3279–3290) and the multiple asperity contact model (Greenwood, J. A., and Williamson, J. B. P., 1966, “Contact of Nominally Flat Surfaces,” Proc. R. Soc. Lond. A, 295, pp. 300–319). The rough surface is modeled as an ensemble of noninteracting asperities with identical radius of curvature and Gaussian distributed heights. By applying the double-Hertz theory to each individual asperity of the rough surface, the total normal forces for the rough surface are derived for loading and unloading stages, respectively, and a prominent adhesion hysteresis associated with dissipation energy is revealed. A dimensionless Tabor parameter is also introduced to account for general material properties. Our analysis results show that both the total pull-off force and the energy dissipation due to adhesive hysteresis are influenced by the surface roughness only through a single adhesion parameter, which measures statistically a competition between compressive and adhesive forces exerted by asperities with different heights. It is also found that smoother surfaces with a small adhesion parameter result in higher energy dissipation and pull-off force, while rougher surfaces with a large adhesion parameter lead to lower energy dissipation and pull-off force.

A New Contact Model of Joint Surfaces Accounting for Surface Waviness and Substrate Deformation

2019 ◽  
Vol 11 (08) ◽  
pp. 1950079
Author(s):  
Ling Li ◽  
Qiangqiang Yun ◽  
Zhiqiang Li ◽  
Yin Liu ◽  
Changyong Cao
Keyword(s):  
Rough Surface ◽  
Rough Surfaces ◽  
Normal Load ◽  
Surface Film ◽  
Contact Model ◽  
Joint Surface ◽  
Real Contact Area ◽  
Surface Waviness ◽  
Proposed Model ◽  
Joint Surfaces

The joint surfaces in the computer numerically controlled (CNC) machines play a crucial role in transmitting load and energy in operations. In this paper, a new contact model between rough surfaces of a joint is proposed by considering the influence of surface waviness and substrate deformation. A contact model for a single asperity system is first established, in which the asperity and substrate deformations are calculated based on the Hertz theory. Then, it is extended to an entire rough surface by a statistical method, where the contact of rough surfaces is treated as the contact between a smooth waviness and a rough surface. The numerical results showed that when contact deformation is constant, the real contact area and the normal load of joint surfaces increase with increasing radius of the waviness peak while the normal load decreases with the increase of surface roughness. When a rough surface contains a coating layer or a surface film, the deformation of the joint surface has to consider both substrate deformation and asperity deformation. The substrate deformation will generate larger influence for a stiffer or harder coating. Compared with other models, the results obtained from the proposed model show better agreements with the experimental data.

Adhesive Elastic Contact of Rough Surfaces with Power-Law Axisymmetric Asperities

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Lefeng Wang ◽  
Weibin Rong ◽  
Bing Shao ◽  
Lining Sun
Keyword(s):  
Power Law ◽  
Adhesion Force ◽  
Rough Surfaces ◽  
Specific Interaction ◽  
Shape Index ◽  
Adhesive Contact ◽  
Contact Model ◽  
Colloid Interface ◽  
Adhesion Performance ◽  
Effect Of Surface

The contact model for rough surfaces with power-law axisymmetric asperities in the presence of adhesion is developed. The extended JKR adhesive contact model for power-law axisymmetric asperities, denoted as JKR-n, developed by Zheng and Yu (2007,“Using the Dugdale Approximation to Match a Specific Interaction in the Adhesive Contact of Elastic Objects,” J. Colloid Interface Sci., 310, pp. 27–34) is utilized to investigate the adhesive contact of rough surfaces. The JKR-n adhesive contact model generalizes the most adopted JKR model for spherical objects of n = 2. This work compares the effect of surface roughness on the adhesion force for rough surfaces with various power-law axisymmetric asperities. It is found that shapes of the asperities influence the pull-off forces greatly during the separation of rough surfaces. A general adhesion parameter that includes the shape index of asperities is proposed, and it can be used to characterize the adhesion performance of rough surfaces.

A New Adaptive-Surface Elastic-Plastic Contact Model of Rough Surfaces: Parameter Correlations

2006 ◽  
Vol 532-533 ◽  
pp. 961-964
Author(s):  
Min Song
Keyword(s):  
Rough Surface ◽  
Root Mean Square ◽  
Rough Surfaces ◽  
Computing Time ◽  
Contact Model ◽  
Asperity Contact ◽  
Mean Square ◽  
Elastic Plastic ◽  
Surface Profiles

Based on an presented adaptive-surface elastic-plastic asperity contact model which can greatly decrease contact computing time and keep the precision loss less than 5%, a series of 2-D rough surface profiles with different roughness and correlative length are numerically generated to investigate how to select the threshold used in this model for different adaptive rough surfaces. The results show that well acceptable precision of the elastic-plastic contact calculation would be derived when the ratio of threshold to root mean square curvature, δ 1.0 10 6mm2 − < × .

A New Numerical Approach for Adhesive Contacts of Real Engineering Surfaces

2010 ◽  
Vol 44-47 ◽  
pp. 1251-1257 ◽  
Author(s):  
Yu Qi Zheng ◽  
San Min Wang
Keyword(s):  
Elastic Deformation ◽  
Meshless Method ◽  
Adhesive Contact ◽  
Adhesive Force ◽  
Viscous Force ◽  
Rigid Spheres ◽  
Dugdale Model ◽  
Nano Scale ◽  
D Model ◽  
Tabor Parameter

Microelectromechanical system (MEMS) and nanotechnology are important directions on the development of the science in twenty-first century. Some of the effects, such as viscous force, surface force, electrostatic force, friction etc., which can be usually ignored on the traditional scale, have become noticeable when the scale has turn to micro or nano scale. Nanotribology is one of the main areas of the indispensable researches on the basic theory and methodology of the effects. The micro/nano adhesive contact which is the foundation of nanotribology is studied in this paper. The earliest study on adhesive contact was done by Bradley. He presented an expression of adhesive force of two contacting rigid spheres. Derjaguin, Muller and Toprov (DMT) gave the relation of the contact area and the applied load of the adhesive contact of two spheres, but they did not consider the elastic deformation due to the adhesive force of the bodies. Johnson, Keudall and Roberts (JKR) provided a theory of the adhesive contact of two elastic spheres. Tabor gave a parameter (Tabor parameter) to interpret the ratio of the elastic deformation with the adhesive force of two contacting bodies. That is to say the DMT model corresponding to small Tabor parameter(<0.1) and the JKR model to large Tabor parameter(>5). Maguis gave a DMT-JKR transition using the Dugdale model in fracture mechanics (M-D model) in the intermediate region between the DMT model and the JKR model. A numerical algorithm of elastic adhesive contact based on the meshless method is presented in this paper. This make it possible to solve the adhesive contact with more complex surface topography and to consider more intricate factors, such as thermal stress, friction, elasto-plastic deformation etc. in the further studies on micro/nano scale adhesive contact problems. The meshless method seems to be a promising approach for contact analyses because of its flexibility in domain descritization and versatility in node arrangements. It can be used to solve a variety of complicated engineering problems. A numerical example of adhesive contact between a micro elastic cylinder and a rigid half-space is carried out to show the feasibility of the algorithm. In the simulation, an effective method of the M-D model is used to save the cost of computation. Compared with the existed solutions, the results solved by the presented algorithm are reasonable.

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.

Reduced Rough-Surface Parametrization for Use With the Discrete-Element Model

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Stephen T. McClain ◽  
Jason M. Brown
Keyword(s):  
Heat Transfer ◽  
Rough Surface ◽  
Surface Characterization ◽  
Rough Surfaces ◽  
Roughness Element ◽  
Three Dimensional ◽  
Element Model ◽  
Discrete Element ◽  
Diameter Distribution ◽  
Discrete Element Model

The discrete-element model for flows over rough surfaces was recently modified to predict drag and heat transfer for flow over randomly rough surfaces. However, the current form of the discrete-element model requires a blockage fraction and a roughness-element diameter distribution as a function of height to predict the drag and heat transfer of flow over a randomly rough surface. The requirement for a roughness-element diameter distribution at each height from the reference elevation has hindered the usefulness of the discrete-element model and inhibited its incorporation into a computational fluid dynamics (CFD) solver. To incorporate the discrete-element model into a CFD solver and to enable the discrete-element model to become a more useful engineering tool, the randomly rough surface characterization must be simplified. Methods for determining characteristic diameters for drag and heat transfer using complete three-dimensional surface measurements are presented. Drag and heat transfer predictions made using the model simplifications are compared to predictions made using the complete surface characterization and to experimental measurements for two randomly rough surfaces. Methods to use statistical surface information, as opposed to the complete three-dimensional surface measurements, to evaluate the characteristic dimensions of the roughness are also explored.

scholarly journals Adhesion of Soft Materials to Rough Surfaces: Experimental Studies, Statistical Analysis and Modelling

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 350 ◽  
Author(s):  
Andrey Pepelyshev ◽  
Feodor Borodich ◽  
Boris Galanov ◽  
Elena Gorb ◽  
Stanislav Gorb
Keyword(s):  
Statistical Analysis ◽  
Smooth Surface ◽  
Rough Surfaces ◽  
Experimental Studies ◽  
Soft Materials ◽  
Adhesive Contact ◽  
Theoretical Modelling ◽  
Height Distribution ◽  
Depth Sensing ◽  
Adhesive Properties

Adhesion between rough surfaces is an active field of research where both experimental studies and theoretical modelling are used. However, it is rather difficult to conduct precise experimental evaluations of adhesive properties of the so-called anti-adhesive materials. Hence, it was suggested earlier by Purtov et al. (2013) to prepare epoxy resin replicas of surfaces having different topography and conduct depth-sensing indentation of the samples using a micro-force tester with a spherical smooth probe made of the compliant polydimethylsiloxane polymer in order to compare values of the force of adhesion to the surfaces. Surprising experimental observations were obtained in which a surface having very small roughness showed the greater value of the force of adhesion than the value for a replica of smooth surface. A plausible explanation of the data was given suggesting that these rough surfaces had full adhesive contact and their true contact area is greater than the area for a smooth surface, while the surfaces with higher values of roughness do not have full contact. Here, the experimental results of surface topography measurements and the statistical analysis of the data are presented. Several modern tests of normality used showed that the height distribution of the surfaces under investigation is normal (Gaussian) and hence the classic statistical models of adhesive contact between rough surfaces may formally be used. Employing one of the Galanov (2011) models of adhesive contact between rough surfaces, the plausible explanation of the experimental observations has been confirmed and theoretically justified.

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