An improved GW model considering the changing curvature radius of asperities
Ban Liren,
Qi Chengzhi,
Shan Renliang,
Chen Haoxiang,
Jiang Kuan,
Xue Yaodong
Affiliations
Ban Liren
School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing 100083, China
Qi Chengzhi
Beijing Future Urban Design High-Tech Innovation Center and 2011 Energy Conservation and Emission reduction Collaborative Innovation Center, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
Shan Renliang
School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing 100083, China
Chen Haoxiang
China PLA University of Science and Technology, Nanjing Jiangsu, 210007, China
Jiang Kuan
Beijing Future Urban Design High-Tech Innovation Center and 2011 Energy Conservation and Emission reduction Collaborative Innovation Center, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
Xue Yaodong
School of Mechanics and Civil Engineering, China University of Mining and Technology, Beijing 100083, China
The classical Greenwood and Williamson (GW) model assumes that the asperity is elastic, which does not take into account the changes of curvature radius of the asperity after wearing.On the basis of classical Hertz contact theory and GW model, the shear stiffness formula of the friction surface was derived when the asperity curvature is constant.According to the Mohr-Coulomb criterion, the yield point position of a single asperity under normal pressure and tangential friction force was discussed.And the critical pressure formula for a single asperity was derived, which showed that the pressure corresponds to the radius of curvature of asperity.A model considering the wear of asperities was proposed and the shear stiffness formula of the friction surface considering the changes of the curvature of the asperity was obtained by combining the shear stiffness formula with a constant curvature radius and the critical pressure formula for a single asperity.The calculation results of the model are in a good agreement with the test results.For the specific roughness of rock surface, with the increase of pressure, the rock surface gradually becomes smooth;for different roughness of rock surface, with the increase of roughness, the rock surface is easier to be smoothed.
