scholarly journals EFFECT OF RATIO OF MATERIAL HARDNESSES, AVERAGE PRESSURE AND ROUGHNESS PARAMETERS ON ACTUAL CONTACT AREA OF ASSEMBLED SURFACES

Author(s):  
M. M. Matlin ◽  
V. A. Kazankin ◽  
E. N. Kazankina ◽  
E. V. Kapinosova

The paper describes the influence of various factors, including the ratio of hardness, average pressure, radius of microasperities of the surface, affecting the value of the actual contact area of rough surfaces of flat parts mated in fixed joints. The study was carried out using the dependences obtained by the authors describing the elastic-plastic contact of rough surfaces.

2021 ◽  
Vol 41 (5) ◽  
pp. 437-438
Author(s):  
K. R. Muratov ◽  
E. A. Gashev ◽  
T. R. Ablyaz ◽  
P. V. Maksimov ◽  
M. S. Permyakov ◽  
...  

1979 ◽  
Vol 101 (1) ◽  
pp. 15-20 ◽  
Author(s):  
A. W. Bush ◽  
R. D. Gibson ◽  
G. P. Keogh

The statistics of a strongly anisotropic rough surface are briefly described. The elastic contact of rough surfaces is treated by approximating the summits of a random process model by parabolic ellipsoids and applying the Hertzian solution for their deformation. Load and real contact area are derived as functions of the separation and for all separations the load is found to be approximately proportional to the contact area. The limits of elastic/plastic contact are discussed in terms of the plasticity index.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Sepehri ◽  
Kambiz Farhang

Three-dimensional elastic-plastic contact of two nominally flat rough surfaces is considered. Equations governing the shoulder-shoulder contact of asperities are derived based on the asperity constitutive relations from a finite element model of the elastic-plastic interaction proposed by Kogut and Etsion (2002), in which asperity scale constitutive relations are derived using piecewise approximate functions. An analytical fusion technique is developed to combine the piecewise asperity level constitutive relations. Shoulder-shoulder asperity contact yields a slanted contact force consisting of two components, one in the normal direction and a half-plane tangential component. Statistical summation of the asperity level contact force components and asperity level contact area results in the total contact force and total contact area formulae between two rough surfaces. Approximate equations are developed in closed form for contact force components and contact area.


2010 ◽  
Vol 154-155 ◽  
pp. 531-534 ◽  
Author(s):  
Zhi Qian Xu ◽  
Xiang Zhen Yan ◽  
Xiu Juan Yang

In this paper, the calculation formulas of the asperity’s deformation related with the surface contact pressure are deduced by using the simplified contact model. Firstly, we assume that the rough surface is composed of a set of cones as asperities, and the cones are arranged in different ways along two directions. Secondly, according to the mechanical analysis of a rigid conical punch on a half-space, the theoretical relationship between the average pressure of the micro contact area and the property parameters of a conical punch is obtained. Meanwhile, the calculation formula of the average pressure is given under the reasonable assumptions, which is related with the asperity’s deformation and the contact pressure. Finally, combining two theoretical relationships above, the quantitative analysis method for micro asperity’s deformation of two rough surfaces in contact is provided by using the average pressure as a connection bridge.


Author(s):  
Shaobiao Cai ◽  
Bharat Bhushan

A numerical three-dimensional contact model is presented to investigate the contact behavior of multilayered elastic-perfectly plastic solids with rough surfaces. The surface displacement and contact pressure distributions are obtained based on the variational principle with fast Fourier transform (FFT)-based scheme. Von Mises yield criterion is used to determine the onset of yield. The effective hardness is modeled and plays role when the local displacement meet the maximum displacement criterion. Simulations are performed to obtain the contact pressures, fractional total contact area, fractional plastic contact area, and surface/subsurface stresses. These contact statistics are analyzed to study the effects of the layer-to-substrate ratios of stiffness and hardness, surface roughness, and layers thickness of rough, two-layered elastic/plastic solids. The results yield insight into the effects of stiffness and hardness of layers and substrates, surface roughness, and applied load on the contact performance. The layer parameters leading to low friction, stiction, and wear are investigated and identified.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Lei Liu ◽  
Shengyou Zhang ◽  
Weidong Liu ◽  
Wei Sun ◽  
Jinxin Li

Proper determination of the shear strength of the backfill body used to fill the subsidence is the basis for subsidence restoration and the stability analysis of materials. This study developed a shear strength calculation model for the backfill body by introducing adhesive friction theory into the shear strength analysis. A direct shear test was performed in the laboratory to verify the proposed method. Test results suggested that the shear strength calculation method based on adhesive friction theory can calculate the variation in the actual contact area between grains in the tested samples undergoing shearing and estimate the peak shear strength. The actual contact area was divided into two components, namely, adhesive contact area Arm and contact area reduction caused by shear displacement, which exhibited a maximum at Armax. The shear strength values calculated by this method were smaller than laboratory values, and their differences increased with the rock proportion in the backfill body. The differences between the theoretical and experimental values of shear strength increased with the rock grain size. The results of theoretical calculation, combined with the results of laboratory experiments, can provide support for the proper determination of shear strength of the backfill body.


Wear ◽  
1971 ◽  
Vol 18 (6) ◽  
pp. 439-448 ◽  
Author(s):  
G.M. Bartenev ◽  
V.V. Lavrentjev ◽  
N.A. Konstantinova

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