Effect of Substrate Shape on Friction Regimes and on Tip Jump Probability in Atomic Scale Friction

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
E. Djiha Tchaptchet ◽  
G. Djuidje Kenmoe ◽  
T. C. Kofane
Keyword(s):  
Friction Force ◽  
Critical Time ◽  
Atomic Scale ◽  
Potential Minimum ◽  
Frictional Behavior ◽  
Substrate Potential ◽  
Effects Of Temperature ◽  
Critical Times

We investigate the effect of the shape potential on the frictional behavior transitions. The Tomlinson parameter for the deformable substrate potential is calculated theoretically and its influence on friction force is studied. Futhermore, effects of temperature and substrate shape on the tip jump probability are presented. We find two critical times, which characterize the tip dynamics. The first critical time is the time spent by the tip to reach next potential minimum and the second is the time at which the tip exhibits an equiprobability of forward and backward jump. We show that these critical times depend strongly on the substrate shape as well as on the temperature.

How buyer roles and critical times affect buyer-supplier exchange episodes

IMP Journal ◽  
2017 ◽  
Vol 11 (3) ◽  
pp. 376-397 ◽  
Author(s):  
William James Newell
Keyword(s):  
Social Space ◽  
Critical Time ◽  
Primary Data ◽  
Common Source ◽  
Content Type ◽  
The Social ◽  
Relationship Change ◽  
Research Stream ◽  
E Mail ◽  
Critical Times

Purpose The purpose of this paper is threefold: first, to examine how buyer-supplier episodes are characterised by their dimensions of time and social space, and how these dimensions interact to impact the criticality of an episode; second, to explore how time and social space create patterns of episodes that lead to buyer-supplier relationship change and continuity; and third, to examine the social space by the different roles that the buyer assumes among their episodes, while focusing on the concept of critical time to denote the temporal context. Design/methodology/approach A case study of a small retailer and five suppliers is employed. The primary data are e-mail communications between the buying and selling firms, along with a two-week field study at the retailer’s location. A total of 2,000 e-mails are coded to yield 75 episodes for the analysis. Findings The criticality of episodes differs depending on the role that the buyer assumes, and whether the episode occurs within a critical time period. The social space affects the type of criticality, while critical times enhance an episode’s criticality. This study outlines five different patterns of episodes occurring within critical times and across social spaces that characterise each of the buyer-supplier relationships. Research limitations/implications This paper focuses on e-mail communication, with little data on interactions occurring outside of this medium. Originality/value To the researcher’s knowledge, this paper is the first to link specific patterns of episode characteristics to the concept of buyer roles. It also examines episodes using e-mail communication, which is not a common source within the IMP research stream.

scholarly journals Effects of temperature and CO2on the frictional behavior of simulated anhydrite fault rock

2014 ◽  
Vol 119 (12) ◽  
pp. 8728-8747 ◽  
Author(s):  
Anne M.H. Pluymakers ◽  
Jon E. Samuelson ◽  
André R. Niemeijer ◽  
Christopher J. Spiers
Keyword(s):  
Fault Rock ◽  
Frictional Behavior ◽  
Effects Of Temperature

Using FEM to study the frictional instability induced by third-body particles confined in frictional interface

2020 ◽  
Vol 72 (10) ◽  
pp. 1239-1244
Author(s):  
Xiaoyu Yan ◽  
Wei Wang ◽  
Xiaojun Liu ◽  
Jimin Xu ◽  
Lihong Zhu ◽  
...  
Keyword(s):  
Peer Review ◽  
Friction Force ◽  
Rough Surfaces ◽  
Lower Surface ◽  
Third Body ◽  
Content Type ◽  
Frictional Behavior ◽  
Macro Scale ◽  
Frictional Interface ◽  
Frictional Instability

Purpose A finite element method (FEM) model of the frictional behavior of two rough surfaces with a group of third-body particles confined by the surface asperities is established. By monitoring the stress distribution, friction force and the displacement of the surfaces, how the frictional instability is induced by these particles is studied. This modeling job aims to explore the relation between the meso-scale behavior and the macro-scale frictional behavior of these particles. Design/methodology/approach By using FEM, a 2D model of two frictional rough surfaces with a group of elastic or elasto-plastic particles confined by surface asperities is established. The Mises stress, macro friction force and displacements of elements are monitored during compressing and shearing steps. Findings The macro friction coefficient is more stable under higher pressure and smaller under higher shearing speed. The dilatancy of the interface is caused by the elevation effect of the particles sheared on the peak of the lower surface, particles collision and third body supporting. The combined effect of particles motion and surface–surface contact will induce high-frequency displacements of surface units in restricted direction. Originality/value Previous studies about third-body tribology are mainly concentrated on the frictional behavior with large number of particles distributed homogeneously across the interface, but this paper focuses on the behavior of third-body particles confined by surface asperities. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0544/

scholarly journals Tuning friction to a superlubric state via in-plane straining

2019 ◽  
Vol 116 (49) ◽  
pp. 24452-24456 ◽  
Author(s):  
Shuai Zhang ◽  
Yuan Hou ◽  
Suzhi Li ◽  
Luqi Liu ◽  
Zhong Zhang ◽  
...  
Keyword(s):  
Atomic Scale ◽  
Atomistic Simulations ◽  
Contact Interface ◽  
Frictional Behavior ◽  
Flexible Materials ◽  
On Demand ◽  
Scale Structures ◽  
Unusual Strain ◽  
Strain Dependent ◽  
Additional Channel

Controlling, and in many cases minimizing, friction is a goal that has long been pursued in history. From the classic Amontons–Coulomb law to the recent nanoscale experiments, the steady-state friction is found to be an inherent property of a sliding interface, which typically cannot be altered on demand. In this work, we show that the friction on a graphene sheet can be tuned reversibly by simple mechanical straining. In particular, by applying a tensile strain (up to 0.60%), we are able to achieve a superlubric state (coefficient of friction nearly 0.001) on a suspended graphene. Our atomistic simulations together with atomically resolved friction images reveal that the in-plane strain effectively modulates the flexibility of graphene. Consequently, the local pinning capability of the contact interface is changed, resulting in the unusual strain-dependent frictional behavior. This work demonstrates that the deformability of atomic-scale structures can provide an additional channel of regulating the friction of contact interfaces involving configurationally flexible materials.

scholarly journals Dynamically induced friction reduction in micro-structured interfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Menga ◽  
F. Bottiglione ◽  
G. Carbone
Keyword(s):  
Rigid Body ◽  
Friction Force ◽  
Friction Reduction ◽  
Interfacial Friction ◽  
Rigid Substrate ◽  
Regular Array ◽  
Elastic Supports ◽  
Frictional Behavior ◽  
Macroscopic Motion ◽  
Elastic Elements

AbstractWe investigate the dynamic behavior of a regular array of in-plane elastic supports interposed between a sliding rigid body and a rigid substrate. Each support is modelled as a mass connected to a fixed pivot by means of radial and tangential elastic elements. Frictional interactions are considered at the interface between the supports and the sliding body. Depending on the specific elastic properties of the supports, different dynamic regimes can be achieved, which, in turn, affect the system frictional behavior. Specifically, due to transverse microscopic vibration of the supports, a lower friction force opposing the macroscopic motion of the rigid body can be achieved compared to the case where no supports are present and rubbing occurs with the substrate. Furthermore, we found that the supports static orientation plays a key role in determining the frictional interactions, thus offering the chance to specifically design the array aiming at controlling the resulting interfacial friction force.

Principles of atomic friction: from sticking atoms to superlubric sliding

2007 ◽  
Vol 366 (1869) ◽  
pp. 1383-1404 ◽  
Author(s):  
Hendrik Hölscher ◽  
André Schirmeisen ◽  
Udo D Schwarz
Keyword(s):  
Present Article ◽  
Friction Force ◽  
Research Field ◽  
Atomic Scale ◽  
Friction Force Microscopy ◽  
Force Microscopy ◽  
Frictional Forces ◽  
Moving Bodies ◽  
Friction Force Microscope ◽  
Made In

Tribology—the science of friction, wear and lubrication—is of great importance for all technical applications where moving bodies are in contact. Nonetheless, little progress has been made in finding an exact atomistic description of friction since Amontons proposed his empirical macroscopic laws over three centuries ago. The advent of new experimental tools such as the friction force microscope, however, enabled the investigation of frictional forces occurring at well-defined contacts down to the atomic scale. This research field has been established as nanotribology. In the present article, we review our current understanding of the principles of atomic-scale friction based on recent experiments using friction force microscopy.

Frictional Behavior of Glass Fiber Reinforced Polyester under Different Loads

2007 ◽  
Vol 561-565 ◽  
pp. 639-642
Author(s):  
Jan Quintelier ◽  
Filip Van den Abeele ◽  
Liesbet De Doncker ◽  
Wim De Waele ◽  
Joris Degrieck ◽  
...  
Keyword(s):  
Friction Force ◽  
Fibre Orientation ◽  
Test Rig ◽  
Trigger Mechanism ◽  
Frictional Behavior ◽  
Glass Fiber Reinforced ◽  
Pin On Disc ◽  
Glass Fibre Reinforced ◽  
The Difference ◽  
Frictional Behaviour

Pultruded glass fibre reinforced polyester where used to investigated the frictional behaviour of the 45° fibre orientation. Therefore, on a rebuild Pin-on-disc test rig, using composite discs and steel pins, the frictional behaviour of these materials is investigated. Due to the indicated fibre orientation, and a simple trigger mechanism, it was possible to distinguish the friction force for different fibre orientations. The classical know orientations, parallel and perpendicular to the direction of sliding provided expected results, for both cases. The ~45° orientation, which is extremely important regarding filament wounded bearings, behaved in both cases similar -- regarding friction force-- in an unexpected way. The friction force of the 45° orientation was higher in all cases, and the amount was similar to the difference between the parallel and perpendicular case. These findings yield the conclusion that the 45° orientations cannot be neglected in frictional studies, and the behaviour of weft-warp structures also determines performance.

Sign in / Sign up

Export Citation Format

Share Document