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Modeling of contact temperatures and their influence on the tribological performance of PEEK and PTFE in a dual-pin-ondisk tribometer

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Friction 2023年第4期11卷 546-566页

作者： Zhibin LIN Ting QU Ke ZHANG Qingbin ZHANG Shengdao WANG Guibin WANG Bingzhao GAO Guowei FAN State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130025China Key Laboratory of High Performance Plastics Ministry of EducationJilin UniversityChangchun 130012China Clean Energy Automotive Engineering Center Tongji UniversityShanghai 201804China College of Instrumentation and Electrical Engineering Jilin UniversityChangchun 130061China

The direct blending of polyether ether ketone(PEEK)with a solid lubricant such as polytetrafluoroethylene(PTFE)improves its tribological performance,but compromises its outstanding mechanical properties and *** these negative effects might be circumvented via the hybrid wear method,the influence of the contact temperature between multiple sliding components acting together is not fully ***,an analytical temperature model considering the influence of both micro-and macro-thermal behavior is extended to predict the contact temperature of a dual-pin-on-disk hybrid wear *** interactions between several heat sources are investigated and experimentally *** analytical results show that the nominal temperature rise of the shared wear track is determined by the combined effect of the heat generated by both pin components,while the rise in flash temperature at the region in contact with each pin component is dependent upon its individual characteristics and working ***,while different temperature peaks can coexist in the shared wear track,the maximum value dominates the performance of the *** the experimentally investigated PEEK–PTFE–steel hybrid wear system,the formation of tribofilms is blocked,and the hybrid wear system fails,when the peak temperature exceeds the glass transition temperature of both pins due to an increase in applied load.

关键词： contact temperature frictional heating dual-pin-on-disk hybrid wear

Numerical Analysis of Rolling-sliding Contact with the frictional Heat in Rail

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 41-49页

作者： LI Wei WEN Zefeng JIN Xuesong WU Lei State Key Laboratory of Traction Power Southwest Jiaotong University

Thermal damage caused by frictional heat of rolling-sliding contact is one of the most important failure forms of wheel and rail. Many studies of wheel-rail frictional heating have been devoted to the temperature field, but few literatures focus on wheel-rail thermal stress caused by frictional heating. However, the wheel-rail creepage is one of important influencing factors of the thermal stress In this paper, a thermo-mechanical coupling model of wheel-rail rolling-sliding contact is developed using thermo-elasto-plastic finite element method. The effect of the wheel-rail elastic creepage on the distribution of heat flux is investigated using the numerical model in which the temperature-dependent material properties are taken into consideration. The moving wheel-rail contact force and the frictional heating are used to simulate the wheel rolling on the rail. The effect of the creepage on the temperature rise, thermal strain, residual stress and residual strain under wheel-rail sliding-rolling contact are investigated. The investigation results show that the thermally affected zone exists mainly in a very thin layer of material near the rail contact surface during the rolling-sliding contact. Both the temperature and thermal strain of rail increase with increasing creepage. The residual stresses induced by the frictional heat in the surface layer of rail appear to be tensile. When the creepage is large, the frictional heat has a significant influence on the residual stresses and residual strains of rail. This paper develops a thermo-meehanical coupling model of wheel-rail rolling-sliding contact, and the obtained results can help to understand the mechanism of wheel/rail frictional thermal fatigue.

关键词： wheel-rail rolling-sliding contact frictional heating creepage residual stress/strain,thermo-elasto-plastic finite element method

Effect of anisotropy on thermoelastic contact problem

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Applied Mathematics and Mechanics(English Edition) 2008年第4期29卷 501-510页

作者： Sakti Pada Barik M.Kanoria P.K.Chaudhuri Departmemt of Mathematics Gobardanga Hindu CollegeKhantura24-Parganas(N)West BengalIndia Department of Applied Mathematics University of Calcutta92A.P.C.RoadKolkata-700009India

This paper is concerned with the stationary plane contact of an insulated rigid punch and a half-space which is elastically anisotropic but thermally conducting. The frictional heat generation inside the contact region due to the sliding of the punch over the half-space surface and the heat radiation outside the contact region are taken into account. With the help of Fourier integral transform, the problem is reduced to a system of two singular integral equations. The equations are solved numerically by using Gauss-Jacobi and trapezoidal-rule quadratures. The effects of anisotropy and thermal effects are shown graphically.

关键词： transversely isotropic medium Fourier transform frictional heating punch heat radiation singular integral equation Fredholm integral equation

Formation of FeNi metal nodules in the Jilin H5 chondrite,the largest stone meteorite in the world

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Acta Geochimica 2023年第6期42卷 961-970页

作者： Xiande Xie Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China

The Jilin H5 chondrite, the largest known stony meteorite in the world, with its No.1 fragment weighing1770 kg. It contains submillimeter-to centimeter-sized FeNi metal particles/nodules. Our optical microscopic and electron microprobe analyses revealed that the formation of metal nodules in this meteorite is a complex and long-term process, The early stage is the thermal diffusion-caused migration and concentration of dispersed metallic material along fractures to form root-hair shaped metal grains during thermal metamorphism of this meteorite. The later two collision events experienced by this meteorite led to the further migration and aggregation of metallic material into the shock-produced cracks and openings to form largersized metal grains. The shock-produced shear movement and frictional heating occurred in this meteorite greatly enhanced the migration and aggregation of metallic material to form the large-sized nodules. It was revealed that the metal nodule formation process in the Jilin H5 chondrite might perform in the solid or subsolidus state, and neither melting of chondritic metal grains nor shock-induced vaporization of bulk chondrite material are related with this process.

关键词： Jilin chondrite Metal nodules Thermal diffusion Shock metamorphism Shear movement frictional heating

A new numerical model of ring shear tester for shear band soil considering friction-induced thermal pressurization

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Journal of Mountain Science 2022年第11期19卷 3302-3313页

作者： ZHAO Neng-hao SONG Kun ZHANG Rong-tang YI Qing-lin School of Civil Engineering and Architecture Wuhan Polytechnic UniversityWuhan 430023China Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University) Ministry of EducationYichang 443002China

In this study,a new numerical model of ring shear tester for shear band soil of landslide was *** special feature of this model is that it considers the mechanism of friction-induced thermal pressurization,which is potentially an important cause of high-speed catastrophic *** key to the construction of this numerical ring shear model is to realize the THM(thermo-hydro-mechanical)dynamic coupling of soil particles,which includes the processes of frictional heating,thermal pressurization,and strength softening during shearing of solid *** of these are completed by using discrete element *** on this new model,the characteristics of shear stress change with shear displacement,as well as the variation of temperature and pore pressure in the specimen,are studied at shear rates of 0.055 m/s,0.06 m/s,0.109 m/s and 1.09 m/s,*** results show that the peak strength and residual strength of specimen are significantly reduced when the mechanism of frictioninduced thermal pressurization is *** greater the shear rate is,the higher the temperature as well as the pore pressure *** effect of shear rate on the shear strength is *** simulation results demonstrate that this model can effectively simulate the mechanism of friction-induced thermal pressurization of shear band soil during ring shear process,and the shear strength softening in the *** new numerical ring shear model established in this study is of great significance for studying the dynamic mechanism of high-speed catastrophic landslides.

关键词： Ring shear model Discrete element method THM coupling frictional heating Thermal pressurization