scholarly journals The Role of Friction and Tangential Compliance on the Resultant Launch Angle of a Golf Ball

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 27
Author(s):  
Erik Henrikson ◽  
Paul Wood ◽  
Chris Broadie ◽  
Tom Nuttall
Keyword(s):  
Theoretical Model ◽  
Coefficient Of Friction ◽  
Coulomb Friction ◽  
Golf Ball ◽  
Golf Club ◽  
The Coefficient Of Friction ◽  
Hertzian Impact ◽  
The Relationship ◽  
Launch Angle

A thorough understanding of how the delivered face angle and club path of a golf club influences the initial launch direction of a golf ball can play a significant role in the design of various club types as well as help players and coaches better understand performance in the field. A theoretical model based on a Hertzian impact formulation with the inclusion of tangential compliance via Coulomb friction is compared to empirical results. This comparison demonstrates that the initial launch direction of a golf ball for a given club path and face angle can be sufficiently predicted by the theoretical model, providing insights into the mechanisms leading to different launch direction percentages relative to face angle for various club types. Additionally, the relationship between launch direction and the coefficient of friction is explored for various angles of incidence.

Prediction of the Coefficient of Friction for Pneumatic Tyres on Hard Pavement

1975 ◽  
Vol 189 (1) ◽  
pp. 259-266
Author(s):  
Shri Kant ◽  
D. L. Prasanna Rao ◽  
M. L. Munjal
Keyword(s):  
Coefficient Of Friction ◽  
Vertical Load ◽  
Contact Patch ◽  
The Coefficient Of Friction ◽  
The Relationship

The relationship between the coefficient of friction and the slip of a flexible wheel, such as the pneumatic tyre, plays a major role in the design of refined braking systems for vehicles. The available data being partly empirical in nature, it was desirable to be able to predict this relationship. In this paper an attempt is made to explain the mechanism defining this relationship for a pneumatic tyre operating on a hard pavement. The distinct roles of the flexibility of the tyre and the sliding of the wheel are identified and utilized in predicting the curve. A model of the tyre is proposed to explain the role of flexibility of the tyre. It is shown that the procedure suggested here can clearly bring out the effects of some of the operating paramenters of the vehicle, such as speed of the vehicle, presence of contaminants in the contact patch, stiffness of the tyre, and vertical load on the wheel.

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.

Investigation of the causes of damage to freight cars during disbanding on non-mechanized sorting slides and development of measures to prevent them

2021 ◽  
pp. 4-13
Author(s):  
S. V. Tankeev ◽  
◽  
A. E. Kolodin ◽  
V. B. Sverdlov ◽  
A. V. Nazarov ◽  
...  
Keyword(s):  
Low Power ◽  
Coefficient Of Friction ◽  
Damage Assessment ◽  
Laboratory Tests ◽  
Rolling Stock ◽  
Third Body ◽  
Normative Documents ◽  
The Coefficient Of Friction ◽  
Loading And Unloading ◽  
The Relationship

The damage assessment of freight cars during shunting and loading and unloading operations was made. The need to review the normative documents regulating the relationship between the owners of rolling stock, owners of non-public tracks and the carrier is noted. The reasons for formation of damage on the wheel pairs of freight cars when disbanding on low-power sorting slides are considered. The conditions for ensuring the deceleration of detachments on non-mechanized sorting slides without damaging the wheels are determined. The analysis of methods for ensuring braking on low-power slides is carried out. A method was chosen to ensure the wheel set rotation by introducing a third body between the rubbing surfaces during the braking of cars, which will take over a part of the resulting heat flow, reducing the temperature and increasing the coefficient of friction in the «wheel-rail» contact zone. A method is proposed to provide braking on the non-mechanized sorting slide during shoe braking by applying a friction compound to a non-working rail. Laboratory tests were carried out, which showed that the introduction of a friction additive can achieve the necessary coefficient of friction to comply with the standard parameters of deceleration of the car in the braking zone.

scholarly journals The Effect of Elemental Composition and Nanostructure of Multilayer Composite Coatings on Their Tribological Properties at Elevated Temperatures

2020 ◽  
Author(s):  
Alexey Vereschaka ◽  
Sergey Grigoriev ◽  
Vladimir Tabakov ◽  
Mars Migranov ◽  
Nikolay Sitnikov ◽  
...  
Keyword(s):  
Elemental Composition ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Elevated Temperatures ◽  
Composite Coatings ◽  
Multilayer Composite ◽  
The Coefficient Of Friction ◽  
The Relationship ◽  
Tribological Parameters ◽  
Adhesion Component

The chapter discusses the tribological properties of samples with multilayer composite nanostructured Ti-TiN-(Ti,Cr,Al,Si)N, Zr-ZrN-(Nb,Zr,Cr,Al)N, and Zr-ZrN-(Zr,Al,Si)N coatings, as well as Ti-TiN-(Ti,Al,Cr)N, with different values of the nanolayer period λ. The relationship between tribological parameters, a temperature varying within a range of 20–1000°C, and λ was investigated. The studies have found that the adhesion component of the coefficient of friction (COF) varies nonlinearly with a pronounced extremum depending on temperature. The value of λ has a noticeable influence on the tribological properties of the coatings, and the nature of the mentioned influence depends on temperature. The tests found that for the coatings with all studied values of λ, an increase in temperature first caused an increase and then a decrease in COF.

Avoiding Adverse Consequences From Digital Addiction and Retaliatory Feedback

2019 ◽  
pp. 701-716
Author(s):  
Ashu M. G. Solo ◽  
Jonathan Bishop
Keyword(s):  
Theoretical Model ◽  
Digital Technologies ◽  
Transitional Flow ◽  
The Internet ◽  
Digital Addiction ◽  
The Relationship

This chapter looks at the role of the participation continuum in helping to improve relationships that have been damaged as a result of digital addiction. Digital addiction in this context refers to what happens when a person with a compulsion who is not getting that compulsion fulfilled turns to the Internet and other digital technologies in order to fill the void. The chapter is a case study of two people called Person D and Person G in order to make them anonymous. Using medical and other records, it was found that a number of different interventions using the participation continuum could have resulted in changes in the relationship in either holding it together or preventing one party from posting malicious and defamatory comments. The chapter found that a theoretical model, with algorithmic principles applied, called the transitional flow of persuasion model would be able to understand the impacts of digital addiction and provide a means to remedy it.

Influence of Surface Roughness on Friction and Contact Resistance in Sliding Electrical Contacts

2007 ◽  
Author(s):  
Dinesh G. Bansal ◽  
Jeffrey L. Streator
Keyword(s):  
Surface Roughness ◽  
Contact Resistance ◽  
Coefficient Of Friction ◽  
Electrical Contact ◽  
Electrical Current ◽  
Electrical Contacts ◽  
Sliding Electrical Contacts ◽  
The Coefficient Of Friction ◽  
Current Densities

An experiment is conducted to investigate the role of surface roughness on the coefficient of friction and contact resistance of sliding electrical contacts. A hemispherical pin is sliding along both smooth and rough 2-meter rail surface. Tests are performed at both low and moderate sliding speed and for a range of electrical current densities, ranging from 0 to about 12 GA/m2. It was found that surface roughness had a significant influence on the coefficient of friction, with the smoother surfaces exhibiting higher coefficients of friction. Contact resistance, on the other hand, did not show as strong an effect of surface roughness, except for a few parameter combinations. At the higher current densities studied (>10 GA/m2), it was found that the contact resistance values tended to be on the order of 1 mΩ, independent of load, speed and roughness. This convergence may be due to presence of liquid metal film at the interface, which established ideal electrical contact.

A Contribution to the Theory of Friction and Wear and the Relationship between them

1976 ◽  
Vol 190 (1) ◽  
pp. 477-488 ◽  
Author(s):  
J. Halling
Keyword(s):  
Shear Stress ◽  
Coefficient Of Friction ◽  
Interfacial Shear Stress ◽  
Failure Criteria ◽  
Elastic Behaviour ◽  
Total Load ◽  
Perfectly Plastic ◽  
The Coefficient Of Friction ◽  
Wear Law ◽  
The Relationship

The nature of the interaction between a rigid spherical asperity and an asperity governed by the stress/strain law [Formula: see text] is studied. The interfacial shear stress is defined by f τmax where 0 < f < 1, τ maxbeing the maximum allowable shear stress at the contact. By integrating the total effect of a population of such surface asperities expressions for the total frictional forces, and the total load are derived. The value of the coefficient of friction is thus obtained and the special conditions for perfectly plastic and elastic behaviour are considered. In both cases the friction coefficient is seen to contain a term defined by the deformation and dependent on surface roughness and a term totally defined by f. Using the same model a fatigue type failure criteria is introduced to predict the volume of wear. It is then possible to produce a wear law which is consistent with experience and which includes the relationship between the wear and the coefficient of friction.

Abusive supervision and workplace deviance: the role of negative reciprocity

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guglielmo Faldetta
Keyword(s):  
Theoretical Model ◽  
Organizational Behavior ◽  
Abusive Supervision ◽  
Workplace Deviance ◽  
Content Type ◽  
Deviant Behaviors ◽  
Negative Reciprocity ◽  
First Time ◽  
The Relationship

Purpose This study aims to explore the process that, from abusive supervision, leads to the different kinds of workplace deviant behaviors, using the norm of negative reciprocity as the main mechanism that can trigger this process. Design/methodology/approach This study is based on a literature review from organizational behavior and reciprocity fields and builds a theoretical model on the relationship between abusive supervision and workplace deviance within organizations. Findings This study develops a theoretical model where abusive supervision causes a feeling of injustice, which can motivate employees to seek revenge in the form of workplace deviant behaviors. Moreover, negative direct balanced reciprocity will moderate the relationship between the desire for revenge and minor interpersonal workplace deviance; negative direct non-balanced reciprocity will moderate the relationship between the desire for revenge and severe interpersonal workplace deviance; negative generalized balanced reciprocity will moderate the relationship between the desire for revenge and minor organizational workplace deviance; negative generalized non-balanced reciprocity will moderate the relationship between the desire for revenge and severe organizational workplace deviance. Originality/value Previous studies have used negative reciprocity as a moderator, but for the first time, it is split in direct and generalized and in balanced and non-balanced. In particular, when direct negative reciprocity is present, the revenge will take the form of interpersonal workplace deviance; when generalized negative reciprocity is present, the revenge will take the form of organizational workplace deviance. On the other side, when balanced reciprocity is present, revenge will take the form of minor workplace deviance, while when non-balanced reciprocity is present, revenge will take the form of severe workplace deviance.

Simulating the Mechanical Properties of a Yarn Based on the Properties and Arrangement of its Fibers Part II: Results of Simulations

1997 ◽  
Vol 67 (5) ◽  
pp. 342-347 ◽  
Author(s):  
Lieva Van Langenhove
Keyword(s):  
Mechanical Properties ◽  
Theoretical Model ◽  
Coefficient Of Friction ◽  
Stress Strain ◽  
Fiber Property ◽  
The Coefficient Of Friction ◽  
Predicted Values

Part I established a theoretical model that was able to predict the stress-strain and torque-strain curves of a yarn. This second part evaluates the model. The influence of fiber and yarn parameters on the predicted values is also discussed. The most critical fiber property is the coefficient of friction.

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