scholarly journals Study on error averaging effects of aerostatic bearing considering rough surface profile

Author(s):  
Xiao-Long Zhao ◽  
Hao Dong ◽  
Jun-An Zhang
2016 ◽  
Vol 44 (3) ◽  
pp. 150-173 ◽  
Author(s):  
Mehran Motamedi ◽  
Saied Taheri ◽  
Corina Sandu

ABSTRACT For tire designers, rubber friction is a topic of pronounced practical importance. Thus, development of a rubber–road contact model is of great interest. In this research, to predict the effectiveness of the tread compound in a tire as it interacts with the pavement, the physics-based multiscale rubber-friction theories developed by B. Persson and M. Klüppel were studied. The strengths of each method were identified and incorporated into a consolidated model that is more comprehensive and proficient than any single, existing, physics-based approach. In the present work, the friction coefficient was estimated for a summer tire tread compound sliding on sandpaper. The inputs to the model were the fractal properties of the rough surface and the dynamic viscoelastic modulus of rubber. The sandpaper-surface profile was measured accurately using an optical profilometer. Two-dimensional parameterization was performed using one-dimensional profile measurements. The tire tread compound was characterized via dynamic mechanical analysis. To validate the friction model, a laboratory-based, rubber-friction test that could measure the friction between a rubber sample and any arbitrary rough surface was designed and built. The apparatus consisted of a turntable, which can have the surface characteristics of choice, and a rubber wheel in contact with the turntable. The wheel speed, as well as the turntable speed, could be controlled precisely to generate the arbitrary values of longitudinal slip at which the dynamic coefficient of friction was measured. The correlation between the simulation and the experimental results was investigated.


2018 ◽  
Vol 125 ◽  
pp. 75-84 ◽  
Author(s):  
Yuqin Wen ◽  
Jinyuan Tang ◽  
Wei Zhou ◽  
Caichao Zhu

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Wei Zhou ◽  
Daiyan Zhao ◽  
Jinyuan Tang ◽  
Jun Yi

AbstractThe peak identification scheme based method (three-point definition) and the spectral moments based method (spectral moment approach) are both widely used for asperity peak modeling in tribology. To discover the differences between the two methods, a great number of rough surface profile samples with various statistical distributions are first randomly generated using FFT. Then the distribution parameters of asperity peaks are calculated for the generated samples with both methods. The obtained results are compared and verified by experiment. The variation rules of the differences between the two methods with statistical characteristics of rough surfaces are investigated. To explain for the discovered differences, the assumptions by spectral moment approach that the joint distribution of surface height, slope and curvature is normal and that the height distribution of asperities is Gaussian, are examined. The results show that it is unreasonable to assume a joint normal distribution without inspecting the correlation pattern of [z], [z′] and [z′′], and that the height distribution of asperities is not exactly Gaussian before correlation length of rough surface increases to a certain extent, 20 for instance.


2019 ◽  
Vol 30 ◽  
pp. 07001
Author(s):  
Vladimir Biryukov ◽  
Vladimir Grachev ◽  
Ekaterina Karakozova ◽  
Sergey Lobin ◽  
Vladimir Shcherbakov

A method for calculating the rough surface reflection coefficient of an electromagnetic wave is proposed. It is shown that the screening surface roughness in waveguides is equivalent to a decrease in conductivity of these surfaces in comparison with values belonging to Schukin-Leontovich boundary conditions for completely smooth surfaces. Examples of calculating the attenuation coefficient in the rectangular waveguide with rough screening surfaces in a terahertz frequency range are presented. The influence of the size and shape of the rough surface profile irregularities on the waveguide attenuation is studied.


Sign in / Sign up

Export Citation Format

Share Document