scholarly journals A Normal Contact Stiffness Model of Joint Surface Based on Fractal Theory

2019 ◽  
Vol 119 (3) ◽  
pp. 459-479
Author(s):  
Kuo Xu ◽  
Yuan Yuan ◽  
Lihua Zhang
Keyword(s):  
Contact Stiffness ◽  
Fractal Theory ◽  
Joint Surface ◽  
Normal Contact ◽  
Stiffness Model ◽  
Normal Contact Stiffness

Normal Contact Stiffness Fractal Geometric Model Based on the Gamma Distribution of Rough Joint Surface

2013 ◽  
Vol 760-762 ◽  
pp. 2064-2067 ◽  
Author(s):  
Jing Fang Shen ◽  
Ke Xiang Wu ◽  
Fei Yang
Keyword(s):  
Convex Body ◽  
Gamma Distribution ◽  
Contact Stiffness ◽  
Geometric Model ◽  
Fractal Theory ◽  
Fractal Model ◽  
Joint Surface ◽  
Engineering Practice ◽  
Normal Contact ◽  
Normal Contact Stiffness

In this article, according to WenShuHua and Zhangxueniang fractal model, we point out the deficiency. Based on the fractal theory and Zhang, Wens contact stiffness fractal model, this paper puts forward Gamma distribution of rough joint surface normal contact stiffness. This paper considers micro convex body for ellipsoid, contact area for elliptic. This is slightly convex body for sphere hypothesis is more close to the actual situation. At the same time by using statistics theory, considering the contact ellipse long, short axis a and b are greater than zero, the assumption of a and b to two-dimensional Gamma distribution, it is more suitable for engineering practice.

A normal contact stiffness model of machined joint surfaces considering elastic, elasto-plastic and plastic factors

2019 ◽  
Vol 234 (7) ◽  
pp. 1007-1016 ◽  
Author(s):  
Yongquan Zhang ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
He Ling ◽  
Wei Fan ◽  
...  
Keyword(s):  
Surface Topography ◽  
Contact Stiffness ◽  
Fractal Theory ◽  
Fractal Model ◽  
Single Pair ◽  
Machined Surface ◽  
Normal Contact ◽  
Joint Surfaces ◽  
Stiffness Model ◽  
Normal Contact Stiffness

Considering the rough surface as a fractal model makes the research of contact parameters more practical. In the fractal model of the machined surface, the parameters describing the surface topography are independent of the measurement resolution. Based on the elastic, elasto-plastic and plastic deformations of a single pair of contact asperities, a normal contact stiffness model using the fractal model for surface topography description is proposed in this paper. The specimens machined by milling and grinding methods are used to verify the proposed contact stiffness model based on the fractal theory. The experimental and theoretical results indicate that the proposed contact stiffness model is appropriate for the machined joint surfaces.

scholarly journals Theoretical and Experimental Study on Normal Contact Stiffness of Joint Surfaces with Surface Texturing

2020 ◽  
Author(s):  
Chao-Chao Yin ◽  
Hai-Hong Huang ◽  
Dan Zhou ◽  
Zhi-Feng Liu
Keyword(s):  
Rough Surface ◽  
Contact Stiffness ◽  
Fractal Theory ◽  
Surface Texturing ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Normal Contact ◽  
Joint Surfaces ◽  
Theoretical Predictions ◽  
Normal Contact Stiffness

Abstract Effects of surface texturing on the normal contact stiffness of joint surfaces had been investigated by experiments in many previous researches; however, there are relatively few theoretical models in this regard. The rough surface with surface texturing can be divided into two parts: the textured zone and the remaining zone, and their theoretical models are established respectively in this research. For the textured zone, the texture is modeled theoretically based on the three-dimensional topographic data obtained via a 3D-CCMP1 type laser profilometer from TRIMOS. For the remaining zone, the model of normal contact stiffness is established based on the fractal theory for the surface topography description and elastic-plastic deformation of surface asperities, and the structure function method is used to calculate the fractal dimension of rough surface profiles. In the experiment, the normal contact stiffness of specimens is obtained under different normal loads, and the test results are compared with the theoretical predictions. The result shows that the predictions of proposed theoretical model are in good agreement with the experimental data. For the joint surfaces with Sa>2.69 μm, the normal contact stiffness can be effectively increased through proper surface texturing.

scholarly journals Statistical Model of Normal Contact Stiffness of Fixed Joint Surface during Unloading after First Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Donghua Yin ◽  
Xueliang Zhang ◽  
Yonghui Chen ◽  
Guosheng Lan ◽  
Yanhui Wang ◽  
...  
Keyword(s):  
Statistical Model ◽  
Statistical Method ◽  
Contact Stiffness ◽  
Nonlinear Function ◽  
Joint Surface ◽  
Normal Contact ◽  
Surface Separation ◽  
Normal Contact Stiffness ◽  
Loading And Unloading ◽  
Simulation Results

Based on Kogut and Etsion’s model (KE model), a statistical method is used to establish a model of normal contact stiffness of fixed joint surface during unloading after first loading. Simulation results show that, for the elastoplastic contact, normal contact stiffness of joint surface is the nonlinear function of mean surface separation during loading and unloading and decreases as the separation increases. For different plasticity indexes, the normal contact stiffness of joint surface varies differently following the change of mean surface separation during loading and unloading.

scholarly journals RESEARCH OF NORMAL CONTACT STIFFNESS OF STRADDLE-TYPE MONORAIL TYRES BASED ON FRACTAL THEORY

Mechanika ◽  
2019 ◽  
Vol 25 (3) ◽  
pp. 248-254
Author(s):  
Zhou Junchao
Keyword(s):  
Contact Stiffness ◽  
Fractal Theory ◽  
Theory Model ◽  
Contact Dynamics ◽  
Contact Theory ◽  
Element Analysis ◽  
Normal Contact ◽  
Theoretical Support ◽  
Physical Tests ◽  
Normal Contact Stiffness

The contact stiffness of on the rough surface of tread interaction (tire-track) ,a significant parameter for the tire-track contact surface, gives rise to direct influences on stiffness and noises of tyres. There is no sufficient theoretical support for the wheel face design due to lack of research on this parameter. To solve  this problem, an innovative method based on the fractal theory and the Hertz contact theory is proposed to estimate tread interaction contact stiffness. The fractal theory model is established to research the influencing factors on normal contact stiffness on the tread surface. Finite element analysis and physical tests have been conducted to make comparisons about the model. According to research results, there is a non-linear relationship between the contact stiffness and the fractal dimension. The research provides theoretical basis for tyre dynamics of straddle-type monorail vehicles and design of the track contact dynamics.

A MODIFIED COMPLETE NORMAL CONTACT STIFFNESS MODEL OF A FRACTAL SURFACE CONSIDERING CONTACT FRICTION

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050081
Author(s):  
CHUNLING WEI ◽  
HUA ZHU ◽  
SHIHUI LANG
Keyword(s):  
Contact Stiffness ◽  
Fractal Dimensions ◽  
Frictional Resistance ◽  
Contact Model ◽  
Contact Friction ◽  
Fractal Surface ◽  
Normal Contact ◽  
Stiffness Model ◽  
Fractal Roughness ◽  
Normal Contact Stiffness

This paper presents a modified complete normal contact stiffness model of a fractal surface considering contact friction. We use this model to study the influence of fractal dimensions and fractal roughness on normal contact stiffness. The fractal micro-contact model of an asperity and the complete length scale contact model of fractal surface (both contrasting classical mechanics) are revised. The influence of frictional resistance at micro-contact interfaces on normal contact stiffness is also considered. Predictions of the new model are found to be in greater agreement with the results of the experiments than the predictions of the original model. The study analyzes the influence of fractal dimensions and fractal roughness on the normal contact stiffness. With the increase of these two fractal parameters, their influences on the normal contact stiffness are opposite and are different under high pressure and low pressure.

Normal Contact Stiffness on Unit Area of a Mechanical Joint Surface Considering Perfectly Elastic Elliptical Asperities

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
J. P. Shi ◽  
K. Ma ◽  
Z. Q. Liu
Keyword(s):  
Contact Area ◽  
Unit Area ◽  
Rough Surfaces ◽  
Contact Stiffness ◽  
Unit Length ◽  
Joint Surface ◽  
Normal Contact ◽  
Mechanical Joint ◽  
Normal Contact Stiffness ◽  
The Relationship

Based on the Greenwood and Williamson theory, an assumption about the contact-area size of asperities on rough surfaces is proposed under the premise that the height of these asperities on rough surfaces is a Gaussian distribution. A formula has been derived to measure the number of asperities on 2D surfaces. The contact stiffness on a unit length of a 1D outline and that on a unit area of 2D surfaces are presented based on a formula for determining the number of asperities. The relationship between macro parameters, such as contact stiffness and micro parameters on the joint surface, is established.

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