scholarly journals Effect of rolling on the friction coefficient in three-body contact

2019 ◽  
Vol 11 (8) ◽  
pp. 168781401987230
Author(s):  
Almira Miftakhova ◽  
Yang-Yuan Chen ◽  
Jeng-Haur Horng
Keyword(s):  
Friction Coefficient ◽  
Half Space ◽  
Spherical Shape ◽  
Viscoelastic Layer ◽  
Body Contact ◽  
Body Interaction ◽  
System Of Particles ◽  
The Coefficient Of Friction ◽  
Three Body ◽  
Interaction Approach

The contact problem of system of particles rolling over a viscoelastic layer bonded to the rigid half-space was considered. Particles have a spherical shape and their radiuses are distributed along Gauss. Earlier, the friction coefficient was obtained for the particles between surfaces in the relative movement of the surfaces using the three-body interaction method. In this study, the contact area was calculated for a system of particles rolling over the viscoelastic layer bonded to the half-space. Using the three-body interaction approach, the friction coefficient was calculated, taking into account the rolling of particles. The results demonstrate that the coefficient of friction, calculated using the three-body model, decreases when the rolling of particles is taken into account.

scholarly journals Resonance-Assisted Hydrogen Bond—Revisiting the Original Concept in the Context of Its Criticism in the Literature

2021 ◽  
Vol 23 (1) ◽  
pp. 233
Author(s):  
Małgorzata Domagała ◽  
Sílvia Simon and Marcin Palusiak
Keyword(s):  
Hydrogen Bond ◽  
Interaction Energy ◽  
Electron Density ◽  
Intermolecular Hydrogen Bond ◽  
Many Body ◽  
Body Interaction ◽  
The Many ◽  
Three Body ◽  
Interaction Approach ◽  
Original Concept

In the presented research, we address the original concept of resonance-assisted hydrogen bonding (RAHB) by means of the many-body interaction approach and electron density delocalization analysis. The investigated molecular patterns of RAHBs are open chains consisting of two to six molecules in which the intermolecular hydrogen bond stabilizes the complex. Non-RAHB counterparts are considered to be reference systems. The results show the influence of the neighbour monomers on the unsaturated chains in terms of the many-body interaction energy contribution. Exploring the relation between the energy parameters and the growing number of molecules in the chain, we give an explicit extrapolation of the interaction energy and its components in the infinite chain. Electron delocalization within chain motifs has been analysed from three different points of view: three-body delocalization between C=C-C, two-body hydrogen bond delocalization indices and also between fragments (monomers). A many-body contribution to the interaction energy as well as electron density helps to establish the assistance of resonance in the strength of hydrogen bonds upon the formation of the present molecular chains. The direct relation between interaction energy and delocalization supports the original concept, and refutes some of the criticisms of the RAHB idea.

Effect of two-body and three-body microcontacts under dry friction on contact characteristics

2017 ◽  
Vol 232 (4) ◽  
pp. 706-719 ◽  
Author(s):  
Horng-Wen Wu ◽  
Yang-Yuan Chen
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Contact Area ◽  
External Load ◽  
Wear Debris ◽  
Elastoplastic Deformation ◽  
Particle Diameter ◽  
Body Contact ◽  
Wide Range ◽  
Three Body

The wear debris generation is unavoidable between the contact interfaces of moving components. In three-body contact instances, friction and wear occur at these separate contact points. This paper discusses the characteristics of the three-body contact comprising the abrasive particle in the interface compared to the two-body contact. The results show that for the wear debris or foreign particles present in the interface of the three-body contact, as external load initially increases, the external load is fully borne by the contact characteristics of particle-to-surface. Until the external load rises to a particular critical external load, it enters the real three-body situation, and the critical external load thus increases with an increase in the ratio of particle diameter to surface roughness. For two contact surfaces, the summit deformation is the elastoplastic deformation in a wide range of external loads. As the external load is lower than the critical external load value of the three-body contact, the contact surface is under the particle-to-surface two-body contact, and the elastic deformation of surface peak has the largest proportion of contact area. When the external load is higher than the critical external load value, the elastoplastic deformation contact area quickly dominates, and the total contact area ratio approximates to the surface-to-surface two-body contact situation. In the range of engineering surface roughness (σ = 50–400 nm), at each external load and surface roughness, the total friction coefficient decreases with the increase in the ratio of particle diameter to surface roughness under the three-body contact, and this shows that the friction coefficient of surface-to-surface contact is larger than that of the sphere wear debris between the contact interface. At the same surface roughness, the friction coefficient may increase or decrease with an increase in the external load because it is determined by particle diameter. At the same ratio of particle diameter to surface roughness and external load, the friction coefficient increases with the decreasing surface roughness.

Radiation of Body Waves Induced by the Sliding of an Elastic Half-Space Against a Rigid Surface

1999 ◽  
Vol 67 (1) ◽  
pp. 1-5 ◽  
Author(s):  
G. G. Adams
Keyword(s):  
Friction Coefficient ◽  
Half Space ◽  
Coefficient Of Friction ◽  
Wave Train ◽  
Tangential Velocity ◽  
Body Waves ◽  
Rigid Surface ◽  
Plane Shear ◽  
Interface Friction ◽  
The Coefficient Of Friction

The steady sliding of a flat half-space against a rigid surface with a constant interfacial coefficient of friction is investigated. It is shown here that steady sliding is compatible with the formation 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 with respect to the elastic medium. The angles of wave propagation are determined by the Poisson’s ratio and by the coefficient of friction. The amplitude of the waves are indeterminant, 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 a rectangular wave train, or a rectangular pulse, can allow for 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. Furthermore it is shown that the apparent friction coefficient decreases with increasing speed even if the interface friction coefficient is speed-independent. This result supports the interpretation of certain friction behavior as being a consequence of the dynamics of the system, rather than strictly as an interface property. In fact no distinction is made between the static and kinetic interface friction coefficients. [S0021-8936(00)02101-2]

scholarly journals The Effect of Co-Deposition of SiC Sub-Micron Particles and Heat Treatment on Wear Behaviour of Ni–P Coatings

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 180
Author(s):  
Donya Ahmadkhaniha ◽  
Lucia Lattanzi ◽  
Fabio Bonora ◽  
Annalisa Fortini ◽  
Mattia Merlin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Friction Coefficient ◽  
Wear Mechanisms ◽  
Composite Coatings ◽  
Wear Behaviour ◽  
Maximum Hardness ◽  
Sic Particles ◽  
Heat Treated ◽  
The Coefficient Of Friction ◽  
The Difference

The purpose of the study is to assess the influence of SiC particles and heat treatment on the wear behaviour of Ni–P coatings when in contact with a 100Cr6 steel. Addition of reinforcing particles and heat treatment are two common methods to increase Ni–P hardness. Ball-on-disc wear tests coupled with SEM investigations were used to compare as-plated and heat-treated coatings, both pure and composite ones, and to evaluate the wear mechanisms. In the as-plated coatings, the presence of SiC particles determined higher friction coefficient and wear rate than the pure Ni–P coatings, despite the limited increase in hardness, of about 15%. The effect of SiC particles was shown in combination with heat treatment. The maximum hardness in pure Ni–P coating was achieved by heating at 400 °C for 1 h while for composite coatings heating for 2 h at 360 °C was sufficient to obtain the maximum hardness. The difference between the friction coefficient of composite and pure coatings was disclosed by heating at 300 °C for 2 h. In other cases, the coefficient of friction (COF) stabilised at similar values. The wear mechanisms involved were mainly abrasion and tribo-oxidation, with the formation of lubricant Fe oxides produced at the counterpart.

scholarly journals Native three-body interaction in superconducting circuits

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
Simon Panyella Pedersen ◽  
K. S. Christensen ◽  
N. T. Zinner
Keyword(s):  
Superconducting Circuits ◽  
Body Interaction ◽  
Three Body

Effect of three-body interaction on the topology of basins of convergence linked to the libration points in the R3BP

2021 ◽  
pp. 105281
Author(s):  
Md Sanam Suraj ◽  
Rajiv Aggarwal ◽  
Md Chand Asique ◽  
Amit Mittal ◽  
Mamta Jain ◽  
...  
Keyword(s):  
Libration Points ◽  
Body Interaction ◽  
Three Body

Experimental study on the relationship between the friction coefficient and interference in locomotive axle press-fitting

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ting Wang ◽  
Hanfei Guo ◽  
Jianjun Qiao ◽  
Xiaoxue Liu ◽  
Zhixin Fan
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Friction Pair ◽  
Rolling Stock ◽  
Content Type ◽  
Press Fitting ◽  
The Press ◽  
The Coefficient Of Friction ◽  
The Relationship ◽  
Locomotive Wheels

PurposeTo address the lack of data in this field and determine the relationship between the coefficient of friction and the interference between locomotive wheels and axles, this study evaluates the theoretical relationship between the coefficient of friction and the interference under elastic deformation.Design/methodology/approachWhen using numerical analyses to study the mechanical state of the contacting components of the wheels and axle, the interference between the axle parts and the coefficient of friction between the axle parts are two important influencing factors. Currently, as the range of the coefficient of friction between the wheel and axle in interference remains unknown, it is generally considered that the coefficient of friction is only related to the materials of the friction pair; the relationship between the interference and the coefficient of friction is often neglected.FindingsA total of 520 press-fitting experiments were conducted for 130 sets of wheels and axles of the HXD2 locomotive with 4 types of interferences, in order to obtain the relationship between the coefficient of friction between the locomotive wheel and axle and the amount of interference. These results are expected to serve as a reference for selecting the coefficient of friction when designing axle structures with the rolling stock, research on the press-fitting process and evaluations of the fatigue life.Originality/valueThe study provides a basis for the selection of friction coefficient and interference amount in the design of locomotive wheels and axles.

INFLUENCE OF NITROGEN FLOW RATE ON FRICTION COEFFICIENT AND SURFACE ROUGHNESS OF TiN COATINGS DEPOSITED ON TOOL STEEL USING ARC METHOD

2007 ◽  
Vol 14 (05) ◽  
pp. 1007-1013 ◽  
Author(s):  
ESAH HAMZAH ◽  
ALI OURDJINI ◽  
MUBARAK ALI ◽  
PARVEZ AKHTER ◽  
MOHD RADZI HJ. MOHD TOFF ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Tool Steel ◽  
Flow Rate ◽  
Physical Vapor Deposition ◽  
Gas Flow ◽  
Cutting Tools ◽  
Gas Flow Rate ◽  
Pin On Disc ◽  
The Coefficient Of Friction

In the present study, the effect of various N 2 gas flow rates on friction coefficient and surface roughness of TiN -coated D2 tool steel was examined by a commercially available cathodic arc physical vapor deposition (CAPVD) technique. A Pin-on-Disc test was carried out to study the Coefficient of friction (COF) versus sliding distance. A surface roughness tester measured the surface roughness parameters. The minimum values for the COF and surface roughness were recorded at a N 2 gas flow rate of 200 sccm. The increase in the COF and surface roughness at a N 2 gas flow rate of 100 sccm was mainly attributed to an increase in both size and number of titanium particles, whereas the increase at 300 sccm was attributed to a larger number of growth defects generated during the coating process. These ideas make it possible to optimize the coating properties as a function of N 2 gas flow rate for specific applications, e.g. cutting tools for automobiles, aircraft, and various mechanical parts.

The Dependence of the Friction Coefficient on the Size and Course of Sliding Speed

2014 ◽  
Vol 693 ◽  
pp. 305-310 ◽  
Author(s):  
Eva Labašová
Keyword(s):  
Friction Coefficient ◽  
Normal Load ◽  
Testing Machine ◽  
Current Component ◽  
Sliding Speed ◽  
Rectangular Shape ◽  
Coefficient Increase ◽  
The Coefficient Of Friction ◽  
Ring Method ◽  
Run Up

The coefficient of friction for the bronze material (CuZn25Al6) with insert graphite beds and other bronze material (CuSn12) are investigated in this paper. Friction coefficient was investigated experimentally by the testing machine Tribotestor`89 which uses the principle of the ring on ring method. The external fixed bushing was exposed to the normal load of the same size in all tests. Process of load was increased from level 50 N to 600 N during run up 300 s, after the run up the appropriate level of load was held. The internal bushing performed a rotational movement with constant sliding speed. The value of sliding speed was changed individually for every sample (v = 0.2 (0.3, 0.4) m.s-1). The forth test had a rectangular shape of sliding speed with direct current component 0.3 m.s-1 and the amplitude 0.1 m.s-1 period 300 s, the whole test took 2100 s. The obtained results reveal that friction coefficient increase with the increase of sliding speed.

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