scholarly journals Comparison of the Influences of Surface Texture and Boundary Slip on Tribological Performances

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Qiyin Lin ◽  
Baotong Li
Keyword(s):  
Surface Texture ◽  
Slip Velocity ◽  
Structure Parameters ◽  
Textured Surfaces ◽  
Slider Bearing ◽  
Boundary Slip ◽  
Surface Textures ◽  
Slip Surfaces ◽  
Texture Structure ◽  
The Relationship

Close attentions have been widely paid to the engineering textured and slip surfaces for improving bearing tribological performances. Comparison studies on the tribological characteristics of slip and textured surfaces are carried out in this work. The analysis results point out that the influences of surface texture and boundary slip on tribological performances of slider bearing are strongly similar. For the determinate surface textures, there is one and only value of slip velocity to make the tribological performances of textured and slip surfaces in agreement. The corresponding relation between the slip velocity and the texture structure parameters is also obtained, and the size of slip velocity is directly related to the texture geometry parameters including its position parameters. This study will help us to further understand the relationship between boundary slip and surface texture and also the slip phenomenon.

scholarly journals Wetting Model of Asphalt on the Aggregate Surface and Its Effect Factors

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
YuHui Pi ◽  
Yan Li ◽  
YingXing Pi ◽  
XiaoYong Tan ◽  
MingMing He
Keyword(s):  
Surface Tension ◽  
Cooling Rate ◽  
Surface Texture ◽  
Initial Temperature ◽  
Effect Factors ◽  
Surface Textures ◽  
Wetting Process ◽  
Texture Size ◽  
Wetting Model ◽  
The Relationship

Wetting is the process where asphalt infiltrates into the aggregate surface, which is important for the bonding between asphalt and aggregates. In this paper, the aggregate surface textures were simplified to V shape, and a wetting model was established to research the effects of initial temperature and cooling rate of asphalt and aggregate surface texture sizes on the wetting process. The results show that the asphalt infiltrates into the aggregate surface texture faster in the preliminary stage and slower in the later stage. Cooling rate and lower initial temperature of asphalt affect the surface tension and viscosity, resulting in a longer wetting process, but the effects of cooling rate could be ignored in actual practice. The relationship between the infiltration ending time and surface texture size was established, and it is found that the infiltration ending time is essentially proportional to the texture depth squared and inversely proportional to the texture width.

Analysis of Rough Porous Inclined Slider Bearing Lubricated With a Ferrofluid Considering Slip Velocity

2019 ◽  
Vol 7 (1) ◽  
pp. 387-396 ◽  
Author(s):  
Mohmmadraiyan M. Munshi ◽  
Ashok R. Patel ◽  
Gunamani Deheri
Keyword(s):  
Slip Velocity ◽  
Slider Bearing

Multiscale Analysis on Friction-Reducing Characteristics of Textured Surface in Nanoscale Sliding Contacts

2011 ◽  
Vol 86 ◽  
pp. 649-652
Author(s):  
Rui Ting Tong ◽  
Geng Liu ◽  
Lan Liu ◽  
Shang Jun Ma
Keyword(s):  
Copper Substrate ◽  
Dynamics Simulation ◽  
Textured Surface ◽  
Face Centered Cubic ◽  
Textured Surfaces ◽  
Sliding Contacts ◽  
Friction Forces ◽  
Surface Textures ◽  
Force Reduction ◽  
Face Centered

A multiscale method coupled molecular dynamics simulation and finite element method is used to investigate two dimensional nanoscale sliding contacts between a rigid cylindrical tip and an elastic face centered cubic copper substrate with textured surface, in which adhesive effects are considered. Two series of nanoscale surface textures with different asperity shape, different asperity heights and different spacing between asperities are designed. Through the friction forces comparisons between smooth surface and textured surfaces, a better shape is advised to indicate that asperity shape plays an important role in friction force reduction. With proper asperity height and proper spacing between asperities, surface textures can reduce friction forces effectively.

scholarly journals Experimental-numerical studies of the effect of cell structure on the mechanical properties of polypropylene foams

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 713-723
Author(s):  
Wei Gong ◽  
Tuan-Hui Jiang ◽  
Xiang-Bu Zeng ◽  
Li He ◽  
Chun Zhang
Keyword(s):  
Mechanical Properties ◽  
Size Distribution ◽  
Cell Size ◽  
Cell Structure ◽  
Structure Parameters ◽  
Cell Size Distribution ◽  
Numerical Studies ◽  
Polypropylene Foam ◽  
The Impact ◽  
The Relationship

AbstractThe effects of the cell size and distribution on the mechanical properties of polypropylene foam were simulated and analyzed by finite element modeling with ANSYS and supporting experiments. The results show that the reduced cell size and narrow size distribution have beneficial influences on both the tensile and impact strengths. Decreasing the cell size or narrowing the cell size distribution was more effective for increasing the impact strength than the tensile strength in the same case. The relationship between the mechanical properties and cell structure parameters has a good correlation with the theoretical model.

Flow Characteristics of a Powder Lubricant in a Slider Bearing

2001 ◽  
Author(s):  
Manjunath Pappur ◽  
M. M. Khonsari
Keyword(s):  
Slip Velocity ◽  
Thrust Bearing ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Slider Bearing ◽  
Systematic Development ◽  
Powder Lubrication ◽  
Insight Into ◽  
Theory And Experiment ◽  
Good Agreement

Abstract This paper deals with a systematic development of theory of powder lubrication with the appropriate formalism based on the fundamentals of fluid mechanics. The theory is capable of predicting flow velocity, fluctuation (pseudo-temperature), powder volume fraction, and slip velocity at the boundaries. An extensive set of parametric simulations covering particle size, surface roughness, volumetric flow, load and speed are performed to gain insight into the performance of a powder lubricated thrust bearing. The results of simulations are compared to the published experimental results. Good agreement between the theory and experiment attests to the capability of the model and its potential for design of powder lubricated bearings.

Enhancing Tribological Conditions in Tube Hydroforming by Using Textured Tubes

2004 ◽  
Author(s):  
Gracious Ngaile ◽  
Mark Gariety ◽  
Taylan Altan
Keyword(s):  
Deformation Behavior ◽  
Hydrodynamic Lubrication ◽  
Tube Hydroforming ◽  
Great Influence ◽  
Tribological Performance ◽  
Tube Surface ◽  
Sliding Velocity ◽  
Textured Surfaces ◽  
Interface Pressure ◽  
Surface Textures

The effects of textured tubes on the tribological performance in Tube Hydroforming (THF) are discussed. Textured surfaces, namely sand blasted, knurled, and as rolled surfaces were tested under various interface pressure and sliding velocity conditions. Sand blasted textured tubes were found to have the best tribological performance. It was also found that the interface pressure has a great influence on the attainment of Micro-Plasto HydroDynamic Lubrication (MPHDL) and Micro-Plasto HydroStatic Lubrication (MPHSL) conditions at the tool-workpiece interface. Preliminary finite element simulations on the deformation behavior of tube surface shows that surface textures can be optimized to enhance tribological performance.

The Influence of Surface Texture on Abrasive Wear

2019 ◽  
Vol 823 ◽  
pp. 33-40 ◽  
Author(s):  
Yu Tong Hu ◽  
Yong Yong He ◽  
Wei Wang
Keyword(s):  
Friction Coefficient ◽  
Femtosecond Laser ◽  
Abrasive Wear ◽  
White Light ◽  
Surface Texture ◽  
Friction Surface ◽  
Surface Texturing ◽  
Experimental Results ◽  
The Relationship ◽  
Main Factor

Friction happens everywhere. Abrasives generated in tribological process will result in secondary wear. Abrasive wear is a kind of rather common but harmful wear, which is the main reason for the damage of fifty-percent mechanical components by friction. Surface texturing is an effective method to improve the tribological and lubricating performance of tribo-pairs. In this paper, with different-size diamond particles added into the lubricant and a surface of the tribo-pairs textured by different parameters (diameter and depth) with femtosecond laser, the relationship between the surface texture and the abrasive wear was researched, and the influence of the texture on the abrasive wear was analyzed. The friction experiments were carried out on UMT3. The microstructures were tested and analyzed by SEM, microscope and White Light Interferometer respectively. The experimental results showed that the size of the surface texture, compared with that of abrasives, is the main factor which determines the friction coefficient. As the size of the surface texture is much bigger than that of the abrasives, the texture can accommodate the abrasives efficiently, and thus the friction coefficient is reduced efficiently.

Effect of Coarse Aggregate Morphology on the Resilient Modulus of Hot-Mix Asphalt

2005 ◽  
Vol 1929 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Pan ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Surface Texture ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Asphalt Mixes ◽  
Aggregate Morphology ◽  
The Relationship

The resilient modulus measured in the indirect tensile mode according to ASTM D 4123 reflects effectively the elastic properties of asphalt mixtures under repeated load. The coarse aggregate morphology quantified by angularity and surface texture properties affects resilient modulus of asphalt mixes; however, the relationship is not yet well understood because of the lack of quantitative measurement of coarse aggregate morphology. This paper presents findings of a laboratory study aimed at investigating the effects of the material properties of the major component on the resilient modulus of asphalt mixes, with the coarse aggregate morphology considered as the principal factor. With modulus tests performed at a temperature of 25°C, using coarse aggregates with more irregular morphologies substantially improved the resilient modulus of asphalt mixtures. An imaging-based angularity index was found to be more closely related to the resilient modulus than an imaging-based surface texture index, as indicated by a higher value of the correlation coefficient. The stiffness of the asphalt binder also had a strong influence on modulus. When the resilient modulus data were grouped on the basis of binder stiffnesses, the agreement between the coarse aggregate morphology and the resilient modulus was significantly improved in each group. Although the changes in aggregate gradation did not significantly affect the relationship between the coarse aggregate morphology and the resilient modulus, decreasing the nominal maximum aggregate size from 19 mm to 9.5 mm indicated an increasing positive influence of aggregate morphology on the resilient modulus of asphalt mixes.

Experimental study on friction coefficient and temperature rise of heavy-load grease-lubricated spherical plain bearings with surface texture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jinlong Shen ◽  
Tong Zhang ◽  
Jimin Xu ◽  
Xiaojun LIU ◽  
Kun Liu
Keyword(s):  
Friction Coefficient ◽  
Temperature Rise ◽  
Surface Texture ◽  
Tribological Performance ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Roughness Parameters ◽  
Heavy Load ◽  
Friction Coefficients ◽  
Content Type

Purpose This paper aims to improve the tribological performance of grease-lubricated spherical plain bearings (SPBs) under heavy load, dimple-type textures were prepared by laser on the outer surface of the inner ring. The influence of roughness parameters of a textured surface on reducing friction coefficient and temperature rise was also explored. Design/methodology/approach This study adopts a laser processing method to fabricate dimple-type textures. Three-dimensional roughness parameters were used to characterize the textured surfaces. The friction coefficients of five SPBs with surface texture and one original commercially available SPB without surface texture under different nominal loads were measured on a self-established test rig. The data of temperature rise were obtained by nine embedded thermal couples. Findings The results indicate that SPBs with textures generally exhibit lower friction coefficients than the original SPB without textures. The dimple depth has a significant influence on improving the tribological performance, which coincides with the analysis by surface roughness parameters. A textured surface with negative Ssk and high Vvc has the minimum temperature rise. Originality/value As it is too difficult to arrange sensors into heavy-load SPBs, there are few reports about the temperature characteristics. Through nine embedded thermal couples, the distribution of temperature rise on the inner ring of SPBs was given in this study. The positive effect of surface texture on reducing temperature rise and friction coefficient was verified, which is beneficial for the design of heavy-load SPBs.

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