For three-dimensional(3D)mono-layer molecular thin-film lubrication,the elasticity of the substrate affects the tribological behaviors of a thin fluid film confined by two solid substrates.To account for the elastic e...For three-dimensional(3D)mono-layer molecular thin-film lubrication,the elasticity of the substrate affects the tribological behaviors of a thin fluid film confined by two solid substrates.To account for the elastic effects,this study establishes a multi-scale method that combines an atomistic description of the near region with a coarse-grained description of the far region of the solid substrate to simulate the thin-film lubrication.It is demonstrated that for a given temperature range and film-substrate coupling strength,the multi-scale method is in excellent agreement with the fully atomistic simulation.This study reveals that the elastic response of the substrate can be effectively rendered in the hybrid scheme.In the application of the multi-scale method to investigate the tribological properties of the multi-layer molecular thin-film lubrication,it is determined that the systematic static friction coefficient monotonously decreases as the molecular layer thickness in the fluid film increases.In comparison to the mono-layer molecular thin-film lubrication,the multi-layer molecular thin-film lubrication plays a role in reducing the friction and wear of the system.展开更多
Based on thermal-stress coupling analysis and material properties studies,the vibration-induced friction process of a special used heavy-load bolt has been simulated.The temperature distribution of the bolt has been c...Based on thermal-stress coupling analysis and material properties studies,the vibration-induced friction process of a special used heavy-load bolt has been simulated.The temperature distribution of the bolt has been calculate with heat radiation and heat convection considered.Also a solid lubricant,polytetrafluoroethylene (PTFE) has bee considered to reduce the friction heat effect.The result shows that,there are very strong heat effect while no lubracant considered,the temperature of the bolt joint increased sharply and up to 700℃,which exceed the allowable temperature range of the steel.When PTFE lubricant has been applied,the temperature of the bolt joint increased to 260 ℃,and the bolt steel can by applied in this satuation.These results provide important guidance for the bolt structure modification and material selection.展开更多
基金This research is supported by the National Natural Science Foundation of China(Grants Nos.11172310 and 11472284)the Chinese Academy of Sciences(CAS)Strategic Priority Research Program(XDB22040403).
文摘For three-dimensional(3D)mono-layer molecular thin-film lubrication,the elasticity of the substrate affects the tribological behaviors of a thin fluid film confined by two solid substrates.To account for the elastic effects,this study establishes a multi-scale method that combines an atomistic description of the near region with a coarse-grained description of the far region of the solid substrate to simulate the thin-film lubrication.It is demonstrated that for a given temperature range and film-substrate coupling strength,the multi-scale method is in excellent agreement with the fully atomistic simulation.This study reveals that the elastic response of the substrate can be effectively rendered in the hybrid scheme.In the application of the multi-scale method to investigate the tribological properties of the multi-layer molecular thin-film lubrication,it is determined that the systematic static friction coefficient monotonously decreases as the molecular layer thickness in the fluid film increases.In comparison to the mono-layer molecular thin-film lubrication,the multi-layer molecular thin-film lubrication plays a role in reducing the friction and wear of the system.
文摘Based on thermal-stress coupling analysis and material properties studies,the vibration-induced friction process of a special used heavy-load bolt has been simulated.The temperature distribution of the bolt has been calculate with heat radiation and heat convection considered.Also a solid lubricant,polytetrafluoroethylene (PTFE) has bee considered to reduce the friction heat effect.The result shows that,there are very strong heat effect while no lubracant considered,the temperature of the bolt joint increased sharply and up to 700℃,which exceed the allowable temperature range of the steel.When PTFE lubricant has been applied,the temperature of the bolt joint increased to 260 ℃,and the bolt steel can by applied in this satuation.These results provide important guidance for the bolt structure modification and material selection.
