Advances in Tribology最新文献_第4页

Experimental and Theoretical Analysis of Zircaloy-4 and AISI 304 Stainless Steel Material Pair in Water Sliding Conditions 锆合金-4与AISI 304不锈钢材料对水中滑动的实验与理论分析

IF 2.6

Advances in Tribology Pub Date : 2018-07-02 DOI: 10.1155/2018/7575216

Neelima Khare, P. K. Limaye, Kulwant Singh, D. T. Jadhav, A. Bute, Navnath Kalel

{"title":"Experimental and Theoretical Analysis of Zircaloy-4 and AISI 304 Stainless Steel Material Pair in Water Sliding Conditions","authors":"Neelima Khare, P. K. Limaye, Kulwant Singh, D. T. Jadhav, A. Bute, Navnath Kalel","doi":"10.1155/2018/7575216","DOIUrl":"https://doi.org/10.1155/2018/7575216","url":null,"abstract":"Current work was simulated for sliding wear interaction of materials of fuel bundle bearing pad (zircaloy-4) and magazine rotor tube (AISI 304 stainless steel) of Indian Pressurised Heavy Water Reactors (PHWRs). A plan of experiments, based on the techniques of Taguchi, was performed. The objective was to establish a correlation between load and sliding speed with the volume loss and coefficient of friction (COF). These correlations were obtained by multiple linear regressions. The treatment of the experimental results is based on the analysis average and the analysis of variance (ANOVA). Worn surface analyses carried out using SEM and wear mechanisms were identified. ANOVA analysis indicated that load factor has a great influence on the coefficient of friction (~73%). COF suddenly increases to high value after a particular contact pressure due to absence of lubricating film and increase in metal to metal contact. Volume loss of AISI 304 stainless steel and zircaloy-4 is highly affected due to load (~90%) and speed (~65%), respectively. Worn surfaces exhibited deformation, adherence, and compaction of material at all PV conditions. Contact pressures above 475 MPa indicated formation of ratcheting mechanisms and formation of fatigue striation marks. Due to low yield strength of AISI 304 SS, volume loss was on higher side than that of Zr-4.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/7575216","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41588951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Recirculation Flow and Pressure Distributions in a Rayleigh Step Bearing 瑞利步进轴承的再循环流量和压力分布

IF 2.6

Advances in Tribology Pub Date : 2018-06-21 DOI: 10.1155/2018/9480636

F. Shen, Chengjin Yan, Jian Dai, Zhaomiao Liu

{"title":"Recirculation Flow and Pressure Distributions in a Rayleigh Step Bearing","authors":"F. Shen, Chengjin Yan, Jian Dai, Zhaomiao Liu","doi":"10.1155/2018/9480636","DOIUrl":"https://doi.org/10.1155/2018/9480636","url":null,"abstract":"Flow characteristics in the Rayleigh step slider bearing with infinite width have been studied using both analytical and numerical methods. The conservation equations of mass and momentum were solved utilizing a finite volume approach and the whole flow field was simulated. More detailed information about the flow patterns and pressure distributions neglected by the Reynolds lubrication equation has been obtained, such as jumping phenomenon around a Rayleigh step, vortex structure, and shear stress distribution. The pressure distribution of the Rayleigh step bearing with optimum geometry has been numerically simulated and the results obtained agreed with the analytical solution of the classical Reynolds lubrication equation. The simulation results show that the maximum pressure of the flow field is at the step tip not on the lower surface and the increment of the strain rate from Navier-Stokes equation is approximately 49 percent greater than that from Reynolds theory at the step tip. It is also shown that the position of the maximum pressure of the lower surface is a little less than the length of the first region. These results neglected by the Reynolds lubrication equation are important for designing a bearing.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/9480636","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45451114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Theoretical Analysis of the Influence of Asperity’s Dimensions Affected by a Scale Factor on the Mixed Lubrication between Parallel Surfaces 尺度因子对平行表面混合润滑粗糙度尺寸影响的理论分析

IF 2.6

Advances in Tribology Pub Date : 2018-06-19 DOI: 10.1155/2018/3702324

F. Robbe-Valloire, R. Progri, T. D. S. Botelho

{"title":"Theoretical Analysis of the Influence of Asperity’s Dimensions Affected by a Scale Factor on the Mixed Lubrication between Parallel Surfaces","authors":"F. Robbe-Valloire, R. Progri, T. D. S. Botelho","doi":"10.1155/2018/3702324","DOIUrl":"https://doi.org/10.1155/2018/3702324","url":null,"abstract":"Mixed lubrication between a given pair of surfaces is directly related to the parameter ηu/p. Any change in microgeometry produces a shift in the transition between the boundary and lubricated regimes. Using an asperity based model including five families of asperities (2 for full fluid lubrication and 3 for local boundary lubrication), we simulate mixed lubricated behavior. Our theoretical results confirm the relation between the mixed regime and the ηu/p parameter. All homothetic changes in microgeometry affecting the vertical and horizontal directions by the same scaling factor Sc induce a shift in the transition. The most interesting result is that this shift is exactly the same if speed u is scaled by 1/Sc with the initial microgeometry. This particular behavior, which is in good agreement with experimental results proposed in the literature, comes from the fact that behavior at each asperity can be written using dimensionless parameters. Most of these parameters are independent to any scaling of the microgeometry and only one, the speed parameter, needs to be artificially scaled in order to remain unchanged by the modification of the microgeometry.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/3702324","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47345094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Effect of Tungsten Carbides on Abrasive Wear of Hardfacing Coatings 碳化钨对堆焊涂层磨粒磨损的影响

IF 2.6

Advances in Tribology Pub Date : 2018-06-04 DOI: 10.1155/2018/4047818

P. Pichler, M. Leitner, F. Grün, J. Hassler

{"title":"Effect of Tungsten Carbides on Abrasive Wear of Hardfacing Coatings","authors":"P. Pichler, M. Leitner, F. Grün, J. Hassler","doi":"10.1155/2018/4047818","DOIUrl":"https://doi.org/10.1155/2018/4047818","url":null,"abstract":"The aim of this study is to investigate the abrasive wear loss as well as the wear mechanisms of hardfacing layers with and without tungsten carbides (WC) included in the matrix in different friction wheel test (FWT) configurations. The FWT setup is varied in regard to the materials of the rotating wheels, whereat steel and rubber materials are utilized to achieve varying wear mechanisms as representative conditions for stone milling as well as low density wood cutting processes. Coatings including fine particles of WC highlight the highest resistance against abrasive wear in rubber wheel testing condition, at which microcutting acts as the dominant effect. In comparison to the hardfacings without WC, the mean material loss majorly decreases by about 75%. On the contrary, the mean material loss of fine WC reinforced coatings increases up to 93% compared to the condition without WC if a steel wheel is utilized as rotating counterpart. Thereby, the coatings with comparably coarse WC reveal the minimum material loss with a decrease over 70% compared to the condition without WC. In conclusion, the inclusion of WC in hardfacing coatings significantly increases the wear resistance. The experimental wear test results highlight the fact that in order to achieve the optimal wear resistance the material characteristics of the hardfacings need to be properly defined considering the predominant wear mechanisms under in-service conditions.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/4047818","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46627231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Viscoelastic Contact Simulation under Harmonic Cyclic Load 谐波循环载荷下粘弹性接触模拟

IF 2.6

Advances in Tribology Pub Date : 2018-05-20 DOI: 10.1155/2018/9432894

S. Spinu

{"title":"Viscoelastic Contact Simulation under Harmonic Cyclic Load","authors":"S. Spinu","doi":"10.1155/2018/9432894","DOIUrl":"https://doi.org/10.1155/2018/9432894","url":null,"abstract":"Characterization of viscoelastic materials from a mechanical point of view is often performed via dynamic mechanical analysis (DMA), consisting in the arousal of a steady-state undulated response in a uniaxial bar specimen, allowing for the experimental measurement of the so-called complex modulus, assessing both the elastic energy storage and the internal energy dissipation in the viscoelastic material. The existing theoretical investigations of the complex modulus’ influence on the contact behavior feature severe limitations due to the employed contact solution inferring a nondecreasing contact radius during the loading program. In case of a harmonic cyclic load, this assumption is verified only if the oscillation indentation depth is negligible compared to that due to the step load. This limitation is released in the present numerical model, which is capable of contact simulation under arbitrary loading profiles, irregular contact geometry, and complicated rheological models of linear viscoelastic materials, featuring more than one relaxation time. The classical method of deriving viscoelastic solutions for the problems of stress analysis, based on the elastic-viscoelastic correspondence principle, is applied here to derive the displacement response of the viscoelastic material under an arbitrary distribution of surface tractions. The latter solution is further used to construct a sequence of contact problems with boundary conditions that match the ones of the original viscoelastic contact problem at specific time intervals, assuring accurate reproduction of the contact process history. The developed computer code is validated against classical contact solutions for universal rheological models and then employed in the simulation of a harmonic cyclic indentation of a polymethyl methacrylate half-space by a rigid sphere. The contact process stabilization after the first cycles is demonstrated and the energy loss per cycle is calculated under an extended spectrum of harmonic load frequencies, highlighting the frequency for which the internal energy dissipation reaches its maximum.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/9432894","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45661886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Performance Evaluation of Jatropha and Pongamia Oil Based Environmentally Friendly Cutting Fluids for Turning AA 6061 麻疯树和麻疯树油基环保切削液车削AA 6061的性能评价

IF 2.6

Advances in Tribology Pub Date : 2018-05-15 DOI: 10.1155/2018/2425619

T. P. Jeevan, S. R. Jayaram

引用次数: 45

Microstructural Evolution in Chroming Coatings Friction Pairs under Dry Sliding Test Conditions 干滑动试验条件下铬涂层摩擦副的微观结构演变

IF 2.6

Advances in Tribology Pub Date : 2018-02-07 DOI: 10.1155/2018/5962153

Xin Wang, Ru-lin Zhang, T. Zhou, Xi-cheng Wei, P. Liaw, R. Feng, Wurong Wang, Rong-bin Li

引用次数: 2

Numerical Investigation of Turbulence Models for a Superlaminar Journal Bearing 超层流滑动轴承湍流模型的数值研究

IF 2.6

Advances in Tribology Pub Date : 2018-01-03 DOI: 10.1155/2018/2841303

A. Ding, Xiao-dong Ren, Xue-song Li, C. Gu

{"title":"Numerical Investigation of Turbulence Models for a Superlaminar Journal Bearing","authors":"A. Ding, Xiao-dong Ren, Xue-song Li, C. Gu","doi":"10.1155/2018/2841303","DOIUrl":"https://doi.org/10.1155/2018/2841303","url":null,"abstract":"With rotating machineries working at high speeds, oil flow in bearings becomes superlaminar. Under superlaminar conditions, flow exhibits between laminar and fully developed turbulence. In this study, superlaminar oil flow in an oil-lubricated tilting-pad journal bearing is analyzed through computational fluid dynamics (CFD). A three-dimensional bearing model is established. CFD results from the laminar model and 14 turbulence models are compared with experimental findings. The laminar simulation results of pad-side pressure are inconsistent with the experimental data. Thus, the turbulence effects on superlaminar flow should be considered. The simulated temperature and pressure distributions from the classical fully developed turbulence models cannot correctly fit the experimental data. As such, turbulence models should be corrected for superlaminar flow. However, several corrections, such as transition correction, are unsuitable. Among all the flow models, the SST model with low-Re correction exhibits the best pressure distribution and turbulence viscosity ratio. Velocity profile analysis confirms that a buffer layer plays an important role in the superlaminar boundary layer. Classical fully developed turbulence models cannot accurately predict the buffer layer, but this problem can be resolved by initiating an appropriate low-Re correction. Therefore, the SST model with low-Re correction yields suitable results for superlaminar flows in bearings.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/2841303","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49093939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

FEM Design of a Cutting-Edge Support System for Micro-GT 微型gt前沿支撑系统的有限元设计

IF 2.6

Advances in Tribology Pub Date : 2018-01-01 DOI: 10.1155/2018/9016906

F. Stefani, R. Francesconi, Andrea Perrone

{"title":"FEM Design of a Cutting-Edge Support System for Micro-GT","authors":"F. Stefani, R. Francesconi, Andrea Perrone","doi":"10.1155/2018/9016906","DOIUrl":"https://doi.org/10.1155/2018/9016906","url":null,"abstract":"The design of the support system (shaft, bearings, and mechanical coupling devices) of the rotor plays a key role in the development of efficient micro-gas turbines (micro-GTs) for distributed power generation. Foil air bearings are the most widespread technical solution well suited to design a reliable support system, although they cannot withstand a large number of start-stop cycles of the units. In order to overcome such limitation, we have recently proposed an innovative support system that takes advantage of spline couplings and two bearing types (e.g., air and rolling-element bearings). The devised support system employs splines as both convenient coupling systems and actuators for the load partition between the two bearing types. In the present work, the helical spline coupling is studied by means of structural FEM analyses including contact simulation in order to design the support system. Numerical results confirm previous findings in that the load transfer through the spline coupling is mainly a function of the helix angle. In addition, friction factor and structural stiffness cannot be neglected in the accurate design of the spline coupling. Such design parameters are now included in the proposed design procedure, which formerly assumed frictionless contact and rigid bodies.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/9016906","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64739025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Expansion of the Metrological Visualization Capability by the Implementation of Acoustic Emission Analysis 通过实施声发射分析扩展计量可视化能力

IF 2.6

Advances in Tribology Pub Date : 2017-08-01 DOI: 10.1155/2017/3718924

P. Bergmann, F. Grün, Florian Summer, I. Gódor, Gabriel Stadler

引用次数: 17