The stick-slip mechanism for granular flow lubrication
Industrial Lubrication and Tribology
ISSN: 0036-8792
Article publication date: 4 December 2018
Issue publication date: 25 January 2019
Abstract
Purpose
Granular flow lubrication is developed in recent years as a new lubrication method which can be used in extreme environments, while the stick-slip mechanisms of granular flow lubrication are an urgent obstacle remains unsolved in fully establishing the granular flow lubrication theory.
Design/methodology/approach
A granular flow lubrication research model is constructed by the discrete element method. Using this numerical model, the mesoscopic and macroscopic responses of stick-slip that influenced by the shear velocity, and the influence of the shear velocity and the normal pressure on the vertical displacement are studied.
Findings
Research results show that movement states of granular flow lubrication medium gradually transform from the stick-slip state to the sliding state with increased shear velocity, in which these are closely related to the fluctuations of force chains and friction coefficients between granules. The stick-slip phenomenon comes up at lower shear velocity prior to the appearance of granular lift-off between the two friction pair, which comes up at higher shear velocity. Higher normal pressure restrains the dilatation of the granular flow lubrication medium, which in turn causes a decrease in the displacement.
Originality/value
These findings reveal the stick-slip mechanism of granular flow lubrication and can also offer the helpful reference for the design of the new granular lubrication bearing.
Keywords
Acknowledgements
This study was supported by the National Natural Science Foundation of China (grant nos. 51605150 and 11472096). This study was also partly supported by the Key Scientific Research Projects of Henan Colleges and Universities (grant nos.19B460002).
Citation
Meng, F. and Liu, K. (2019), "The stick-slip mechanism for granular flow lubrication", Industrial Lubrication and Tribology, Vol. 71 No. 1, pp. 139-145. https://doi.org/10.1108/ILT-07-2018-0295
Publisher
:Emerald Publishing Limited
Copyright © 2018, Emerald Publishing Limited