Modelling for water-based liquid lubrication with ultra-low friction coefficient in rough surface point contact

2020 ◽  
Vol 141 ◽  
pp. 105901 ◽  
Author(s):  
Yanfei Fang ◽  
Liran Ma ◽  
Jianbin Luo
Keyword(s):  
Friction Coefficient ◽  
Rough Surface ◽  
Point Contact ◽  
Surface Point ◽  
Low Friction ◽  
Water Based

Effects of Differential Scheme and Viscosity Model on Rough-Surface Point-Contact Isothermal EHL

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Yuchuan Liu ◽  
Q. Jane Wang ◽  
Dong Zhu ◽  
Wenzhong Wang ◽  
Yuanzhong Hu
Keyword(s):  
Experimental Data ◽  
Rough Surface ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Second Order ◽  
Surface Point ◽  
Computational Accuracy ◽  
First Order ◽  
Volume Viscosity ◽  
Differential Scheme

This paper discussed the computational accuracy of rough-surface point-contact isothermal elastohydrodynamic lubrication (EHL) analysis by investigating the effects of differential scheme, viscosity-pressure, and shear-thinning models. An EHL experiment with multitransverse ridges was employed as simulated target. Four differential schemes, including the combined and the separate first-order and second-order backward schemes, were investigated. It is found that the separate second-order backward scheme offers the best results based on the comparison with the experimental data, with which two roughness derivatives may be fully or partially canceled each other; thus, the discretization error induced by roughness can be reduced. The consistency of differential schemes is an important issue for the separate schemes. The Yasutomi free-volume viscosity-pressure model and the Eyring rheological model are found to yield the numerical simulations the closest to experimental results.

scholarly journals Stress Analysis of Multilayered Coatings Subjected to Surface Point Contact Loading Based on Its Three-Dimensional Elastic Field Solution

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 838
Author(s):  
Tingjian Wang ◽  
Yue Wu ◽  
Zhihui Qi ◽  
Yang Zhao ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Three Dimensional ◽  
Point Contact ◽  
Elastic Field ◽  
Surface Point ◽  
Contact Loading ◽  
Multilayered Coatings ◽  
Field Solution ◽  
Structural Layout ◽  
Present Solution

In order to investigate the effect of the structural layout of multilayered coatings on its mechanical behavior, a three-dimensional elastic field solution is developed for multilayered solids subjected to surface point contact loading, which is converted from the elastic field solution in frequency domain by using a numerical conversion algorithm. The elastic field solution in frequency domain is obtained by numerically solving a group of linear equations involving the unknown constants in the general elastic field solution of layered material that is obtained by using Fourier integral transform technique. The present solution is validated by comparing with the exact analytical solution for uncoated solids and finite element solution for solids coated with 30 layers. Lastly, the effect of structural layout of multilayered coatings is further investigated with present solution. The result shows that the gradient structural layout with elasticity modulus decreasing gradually from the top layer to the substrate, which is preferable to a larger friction coefficient for multilayered solids subjected to surface line contact loading, is preferable for a smaller friction coefficient <0.1 for multilayered solids subjected to surface point contact loading, and the gradient structural layout with elasticity modulus increasing first in the top layers and then decreasing in the bottom layers, which is preferable to a smaller friction coefficient for multilayered solids subjected to surface line contact loading, is preferable for a friction coefficient >0.2.

Tribological Behavior of PTFE Nanocomposites Reinforced with PBA Grafted Alumina Nanoparticles

2012 ◽  
Vol 184-185 ◽  
pp. 1380-1383
Author(s):  
Yong Ping Niu ◽  
Xiang Yan Li ◽  
Jun Kai Zhang ◽  
Ming Han ◽  
Yong Zhen Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Tribological Behavior ◽  
Compression Molding ◽  
Alumina Nanoparticles ◽  
Low Friction ◽  
Grafted Nanoparticles ◽  
Scanning Electron

Polybutyl acrylate (PBA) grafted alumina nanoparticles were synthesized. Polytetrafluoroethylene (PTFE) nanocomposites reinforced with PBA grafted nanoparticles were prepared by compression molding. The effects of PBA grafted nanoparticles on the tribological behavior of the PTFE nanocomposites were investigated on a tribometer. The abrasion mechanisms of the PTFE nanocomposites were investigated by scanning electron microscopy (SEM) of the abraded surfaces. The results show that the addition of PBA grafted nanoparticles maintains low friction coefficient and improves the wear resistance of the PTFE nanocomposites.

scholarly journals A thermal resistances-based approach for thermal-elastohydrodynamic calculations in point contacts

2017 ◽  
Vol 232 (11) ◽  
pp. 2088-2102 ◽  
Author(s):  
Eduardo de la Guerra Ochoa ◽  
Javier Echávarri Otero ◽  
Enrique Chacón Tanarro ◽  
Benito del Río López
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Thermal Effects ◽  
Good Accuracy ◽  
Computational Cost ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Point Contacts ◽  
New Approach ◽  
Ball On Disc

This article presents a thermal resistances-based approach for solving the thermal-elastohydrodynamic lubrication problem in point contact, taking the lubricant rheology into account. The friction coefficient in the contact is estimated, along with the distribution of both film thickness and temperature. A commercial tribometer is used in order to measure the friction coefficient at a ball-on-disc point contact lubricated with a polyalphaolefin base. These data and other experimental results available in the bibliography are compared to those obtained by using the proposed methodology, and thermal effects are analysed. The new approach shows good accuracy for predicting the friction coefficient and requires less computational cost than full thermal-elastohydrodynamic simulations.

Observation of Cracks of PEEK Polymer Thrust Bearings under Rolling Contact Fatigue in Water

2016 ◽  
Vol 703 ◽  
pp. 172-177 ◽  
Author(s):  
Xiao Chen Shi ◽  
Masaya Orito ◽  
Yuji Kashima ◽  
Koshiro Mizobe ◽  
Katsuyuki Kida
Keyword(s):  
Corrosion Resistance ◽  
Friction Coefficient ◽  
Cross Sections ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Light Weight ◽  
Low Friction ◽  
High Corrosion Resistance ◽  
Thrust Bearings

Considering the advantages on light weight, low friction coefficient, high corrosion resistance and electric insulation, polymer bearings are widely used under certain environments, where the toughness like metal bearings is not necessary. In our previous study, it was concluded that the main reason for PEEK thrust bearings failure in water was flaking due to surface crack propagation. In the present study, crack observations were made on groove surfaces and cross sections along both radial and rolling directions in order to find the relation between cracks and flaking failures.

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