scholarly journals Molecular Dynamics Study on the Tribological Properties of Phosphorene/Polyethylene Composites

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 342 ◽  
Author(s):  
Yong Peng ◽  
Jiahao Li ◽  
Xianqiong Tang ◽  
Wei Yang ◽  
Xuanzhen Chen ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Potential Energy ◽  
Friction Force ◽  
Coefficient Of Friction ◽  
Tangential Velocity ◽  
Friction Behavior ◽  
Positive Effects ◽  
Number Of Layers ◽  
Abrasion Rate ◽  
The Coefficient Of Friction

This study aimed to investigate the mechanism of phosphorene in enhancing the friction behaviors of polyethylene using molecular dynamics. A sliding model was constructed to investigate the coefficient of friction and abrasion rate of composites by applying a tangential velocity on a rigid tip. Both the size and number of layers of phosphorene had positive effects on the friction force of composites but through different mechanisms. The former was because the interaction between phosphorene and polyethylene increased with the size of phosphorene, while the latter was through influencing the thermal transport across phosphorene and polyethylene interfaces. The rate of improvement decreased with the increased layer number of phosphorene due to the fact that the phosphorene tended to congregate together and thus formed multi-layer agglomerates. The friction behavior of the composites was highly anisotropic because of the high divergence of potential-energy on the phosphorene surface. These findings have provided insights into enhancing the friction behavior of polymer filled by phosphorene.

Investigation of the friction behavior of plasma spray Mo/NiCrBSi coated brake discs

2021 ◽  
Vol 63 (3) ◽  
pp. 259-265
Author(s):  
Halil Kılıç ◽  
Cenk Mısırlı ◽  
İbrahim Mutlu
Keyword(s):  
Coefficient Of Friction ◽  
Plasma Spray ◽  
Wear Behavior ◽  
Atmospheric Plasma ◽  
Brake Disc ◽  
Friction Behavior ◽  
Braking Performance ◽  
Spray Process ◽  
The Coefficient Of Friction ◽  
Nicrbsi Coating

Abstract This paper presents the findings of comparative research conducted to find out the braking performance of a Mo/NiCrBSi coated automobile brake disc. The friction and wear behavior of the Mo/NiCrBSi coating (CD) used for the disc material was evaluated using a laboratory scale disc-pad dynamometer and compared with a reference disc (RD). The coating was deposited by means of the atmospheric plasma spray process on a grey cast iron substrate. Braking tests were performed according to the SAE-J2430 test standard. Disc microstructures were characterized by SEM and XRD. It was found that the bonding strength was good with an infinite rating between the accumulated coating layer and the substrate. The results show that the coated brake disc has a comparable coefficient of friction and that the amount of wear is lower than that of the reference disc. The addition of ductile phases to the disc coating was beneficial in reducing the coefficient of friction to an acceptable degree and also effectively improving wear resistance.

A novel nonlinear nano-scale wear law for metallic brake pads

2018 ◽  
Vol 20 (17) ◽  
pp. 12027-12036 ◽  
Author(s):  
Sandeep P. Patil ◽  
Sri Harsha Chilakamarri ◽  
Bernd Markert
Keyword(s):  
Molecular Dynamics ◽  
Temperature Distribution ◽  
Coefficient Of Friction ◽  
Friction And Wear ◽  
Brake Pads ◽  
Braking System ◽  
System P ◽  
The Coefficient Of Friction ◽  
Dynamics Simulations ◽  
Wear Law

In the present work, molecular dynamics simulations were carried out to investigate the temperature distribution as well as the fundamental friction characteristics such as the coefficient of friction and wear in a disc-pad braking system.

ON THE FRICTION OF INFLATED RUBBER TIRES ON ICE

1958 ◽  
Vol 36 (5) ◽  
pp. 599-610 ◽  
Author(s):  
C. D. Niven
Keyword(s):  
Friction Force ◽  
Coefficient Of Friction ◽  
Sliding Friction ◽  
Rolling Friction ◽  
The Other ◽  
Slow Speed ◽  
Dry Ice ◽  
Load Axis ◽  
Cold Room ◽  
The Coefficient Of Friction

The friction on ice of some small inflated rubber tires was measured on a turntable in a cold room. When rolling-friction force was plotted against load, the relation was either linear or slightly curved away from the load axis; such curvature implies that Thirion's Law does not hold for rolling friction. On the other hand when sliding-friction force was plotted against load the curvature was toward the load axis as would be expected if Thirion's Law applied. The coefficient of friction can go as low as 0.01 or even lower for a hard-pumped tire when the temperature is near 0 °C, but at −1 °C. rolling friction on dry ice is quite appreciable. The results refer only to measurements at very slow speed.

scholarly journals Friction Behavior of Pre-Damaged Wet-Running Multi-Plate Clutches in an Endurance Test

Lubricants ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 68
Author(s):  
Thomas Schneider ◽  
Katharina Voelkel ◽  
Hermann Pflaum ◽  
Karsten Stahl
Keyword(s):  
Coefficient Of Friction ◽  
Later Life ◽  
Second Step ◽  
Experimental Investigations ◽  
Endurance Test ◽  
Friction Behavior ◽  
Speed Range ◽  
The Coefficient Of Friction ◽  
Endurance Tests

Wet-running multi-plate clutches should be prevented from failing due to the often safety-relevant functions they fulfill in the drive train. In addition to long-term damage, spontaneous damage is of particular relevance for failures. This paper focuses on the influence of spontaneous damage on frictional behavior in the later life cycle. The aim of the experimental investigations is to initially cause spontaneous damage in wet-running multi-plate clutches with sintered friction linings. For this purpose, three clutches are first pre-damaged in stage tests with different intensities, so that the first spontaneous damage (local discoloration, sinter transfer) occurs. In the second step, an endurance test is carried out with the pre-damaged clutch packs and a non-pre-damaged reference clutch. The friction behavior of the clutches during the endurance test is compared and evaluated. It shows that local discoloration and sinter transfer are no longer visible after the endurance tests. At the beginning of the endurance test, the values of coefficient of friction are higher over the entire speed range of the heavily pre-damaged clutches than with the slightly pre-damaged clutch and the non-pre-damaged reference clutch. At the end of the endurance test, it can be observed that the greater the pre-damage to the clutches is, the greater the coefficient of friction increases with decreasing sliding speed.

Friction Reduction in the Sliding of an Elastic Half-Space Against a Rigid Surface Due to Incident Rectangular Dilatational Waves

1999 ◽  
Vol 122 (1) ◽  
pp. 10-15 ◽  
Author(s):  
George G. Adams
Keyword(s):  
Normal Stress ◽  
Half Space ◽  
Coefficient Of Friction ◽  
Tangential Velocity ◽  
Elastic Half Space ◽  
Body Waves ◽  
Friction Reduction ◽  
Rigid Surface ◽  
Rectangular Wave ◽  
The Coefficient Of Friction

The steady sliding of a flat homogeneous and isotropic elastic half-space against a flat rigid surface, under the influence of incident plane dilatational waves, is investigated. The interfacial coefficient of friction is constant with no distinction between static and kinetic friction. It is shown here that the reflection of a harmonic wave under steady sliding consists of a pair of body waves (a plane dilatational wave and a plane shear wave) radiated from the sliding interface. Each wave propagates at a different angle such that the trace velocities along the interface are equal and supersonic. The angles of wave propagation are determined by the angle of the incident wave, by the Poisson’s ratio, and by the coefficient of friction. The amplitude of the incident waves is subject only to the restriction that the perturbations in interface contact pressure and tangential velocity satisfy the inequality constraints for unilateral sliding contact. It is also found that an incident rectangular wave can allow for relative sliding motion of the two bodies with a ratio of remote shear to normal stress which is less than the coefficient of friction. Thus the apparent coefficient of friction is less than the interface coefficient of friction. This reduction in friction is due to periodic stick zones which propagate supersonically along the interface. The influences of the angle, amplitude, and shape of the incident rectangular wave, the interfacial friction coefficient, the sliding speed, and of the remotely applied normal stress, on friction reduction are determined. Under appropriate conditions, the bodies can move tangentially with respect to each other in the absence of an applied shear stress. [S0742-4787(00)00201-0]

Influence on Friction Force of Adhesion Force between Vulcanizates and Sliders

1994 ◽  
Vol 67 (5) ◽  
pp. 797-805 ◽  
Author(s):  
Kunio Mori ◽  
Satoshi Kaneda ◽  
Kentaro Kanae ◽  
Hidetoshi Hirahara ◽  
Yoshiyuki Oishi ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Friction Force ◽  
Coefficient Of Friction ◽  
Adhesion Force ◽  
High Surface ◽  
Low Surface Energy ◽  
Polar Groups ◽  
Slider Surface ◽  
The Coefficient Of Friction

Abstract The effects of vulcanizate and slider surface free energy—as well as the adhesion force (P) between them—on friction the force (F) and the coefficient of friction (μ) has been investigated. SBR and NBR vulcanizates were prepared using three molds differing in surface free energy. The mold with a high surface free energy gave a vulcanizate surface possessing polar groups. The mold with low surface energy gave a vulcanizate surface with many nonpolar groups. The coefficient of friction increased with the surface free energy of SBR and NBR vulcanizates. With SBR vulcanizate (surface free energy, 31.3 mJ·m−2) and teflon slider (surface free energy, 28.1 mJ·m−2) combination having the least surface free energy, the coefficient of friction was constant at greater than a 0.2N load. With vulcanizates and an aluminum slider with high surface free energy, friction force could be detected even at zero load because of the adhesion force at the interface. Friction force increased linearly with adhesion force between vulcanizates and sliders when the physical properties of the vulcanizates and net work chain density were constant. The present results clearly demonstrate the contribution of adhesion force to the friction of vulcanizates.

Determining the Coefficient of Friction for Rolling Disks

1978 ◽  
Vol 100 (1) ◽  
pp. 25-30
Author(s):  
D. H. Offner ◽  
N. Tomita
Keyword(s):  
Potential Energy ◽  
Coefficient Of Friction ◽  
Surface Deformation ◽  
Empirical Relationship ◽  
Rolling Resistance ◽  
Experimental Results ◽  
Testing Device ◽  
The Coefficient Of Friction ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

A method and testing device for determining a coefficient of friction for rolling disks is described. The method equates the energy of rolling resistance to the change in potential energy of a moving system. The experimental results of applying this method to steel, aluminum, and plexiglass disks of 3.8, 2.5, and 1.7 cm radii and 1 cm width rolling on steel and aluminum bases are summarized. An empirical relationship between the coefficient of friction and energy of surface deformation is presented. Use of device for determining the static coefficient of friction for impending rolling and sliding of disks is discussed.

scholarly journals Test on a brake lining damper for structures

1985 ◽  
Vol 18 (3) ◽  
pp. 280-284 ◽  
Author(s):  
R. G. Tyler
Keyword(s):  
Friction Force ◽  
Coefficient Of Friction ◽  
Relative Motion ◽  
Steel Plate ◽  
Hysteresis Loops ◽  
Continuous Movement ◽  
The Coefficient Of Friction ◽  
Brake Lining

Tests were carried out on a brake lining damper intended to dissipate energy between parts of a structure having relative motion during earthquake attack. The device operates by the sliding of a steel plate clamped against a brake lining. Hysteresis loops for the damper showed peaks for the breakaway friction force, when the value of the force was up to twice that obtained for continuous movement. Also values of the coefficient of friction derived from the test were lower than those quoted elsewhere. Further testing is required prior to the use of the method in structures.

Friction Characteristics of Porous Rubber Under Wet Conditions

2009 ◽  
Author(s):  
Yutaro Kosugi ◽  
Tomoaki Iwai ◽  
Yutaka Shokaku ◽  
Naoya Amino
Keyword(s):  
Friction Force ◽  
Coefficient Of Friction ◽  
Contact Surface ◽  
Road Surface ◽  
Water Removal ◽  
The Road ◽  
Rubber Specimen ◽  
The Coefficient Of Friction ◽  
The Difference ◽  
Tread Rubber

In recent years, porous rubber has been used as a tread matrix for studless tires. It is said that the pores in the tread rubber remove water between the tire and the wet road surface; however, the water removal is not sufficiently well understood. In this study, a rotating rubber specimen was rubbed against a mating prism to observe the contact surface. The friction force was also measured simultaneously with observation of contact surface. The water entering the pores was distinguished by the continuity method. As the result of these experiments, the coefficient of friction for rubber having pores on the surface was found to be larger than that of rubber without pores. Moreover, the difference in the coefficient of friction for rubber specimens with and without pores tended to be larger at lower sliding speeds. No water entered pores 3mm or less in diameter at any sliding speed in this experiment. An experiment to make the rubber specimen collide with the mating prism was conducted since actual tires seem to be deformed by the vehicle weight, such that the tire surface might contact the road collisionally. In the resulting collision experiment, the water did enter pores 3mm in diameter.

Sign in / Sign up

Export Citation Format

Share Document