Normal displacement and dynamic friction characteristics in a stick-slip process

An analysis is developed for the time-variable friction during the start-up of a rotor system. The analysis is based on a dynamic friction model that has been developed from the theory of unsteady lubrication and can describe the observed friction characteristics. The model reduces to the Stribeck curve of friction versus steady velocity, and shows hysteresis curves in oscillating velocity. The “Dahl effect” of a presliding displacement before the breakaway is also included. The results indicate that the friction characteristics and energy friction losses, during the start-up, depend on a set of dimensionless parameters that represent the bearing as well as the dynamic system. The study shows that appropriate design and operation can prevent stick-slip friction and minimize wear during start-up.

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Dynamic Behaviour of Plain Slideways

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1966_181_019_02 ◽

1966 ◽

Vol 181 (1) ◽

pp. 169-184 ◽

Cited By ~ 19

Author(s):

R. Bell ◽

M. Burdekin

Keyword(s):

Machine Tool ◽

Dynamic Behaviour ◽

Damping Capacity ◽

Friction Characteristic ◽

Stick Slip ◽

Friction Characteristics ◽

Physical Systems ◽

Major Emphasis

The friction characteristics resulting from the motion of one surface over another form a very important facet of the behaviour of many physical systems. This statement is particularly valid when considering the behaviour of machine tool slideways. Most slideway elements consist of two plain surfaces whose friction characteristic is modified by the addition of a lubricant. In many cases the complete slideway consists of many mating surfaces and the choice of slideway material, slideway machining and lubricant is often influenced by the long term problem of wear. The aim of this paper is to present results of experiments on a test rig designed to be representative of machine tool slideway conditions; the experiments were wholly concerned with the behaviour of the bearing under dynamic conditions. The major emphasis is on results obtained with a polar additive lubricant which appears to exclude the possibility of ‘stick-slip’ oscillations. A parallel series of tests are reported where a normal hydraulic oil was used as lubricant. The use of this second lubricant allowed some study of the ‘stick-slip’ process. The dynamic friction characteristics, cyclic friction characteristics and damping capacity of several slideway surface combinations have been obtained and are discussed in the context of earlier work in the field and the role of slideways in machine tool behaviour.

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Experimental Study on the Transition between Static and Kinetic Frictions of Steel/Shale Pairs

Shock and Vibration ◽

10.1155/2021/2764803 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Qin Lian ◽

Chunxu Yang ◽

Jifei Cao

Keyword(s):

Friction Coefficient ◽

Normal Load ◽

Critical Distance ◽

Dynamic Friction ◽

Stick Slip ◽

Dynamic Friction Coefficient ◽

The Coefficient Of Friction ◽

The Difference ◽

Stick Slip Motion ◽

Insight Into

The transition between static and kinetic frictions of steel/shale pairs has been studied. It was found that the coefficient of friction decreased exponentially from static to dynamic friction coefficient with increasing sliding displacement. The difference between static and dynamic friction coefficients and the critical distance Dc under the dry friction condition is much larger than that under the lubricated condition. The transition from static to dynamic friction coefficient is greatly affected by the normal load, quiescent time, and sliding velocity, especially the lubricating condition. Maintaining continuous lubrication of the contact area by the lubricant is crucial to reduce or eliminate the stick-slip motion. The results provide an insight into the transition from static to dynamic friction of steel/shale pairs.

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A Stick-Slip Interactions Model of Soft-Solid Frictional Contacts

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4042247 ◽

2019 ◽

Vol 141 (4) ◽

Cited By ~ 5

Author(s):

Hongbiao Xiang ◽

Mitja Trkov ◽

Kaiyan Yu ◽

Jingang Yi

Keyword(s):

Network Structure ◽

Systems Design ◽

Friction Model ◽

Dynamic Friction ◽

Interaction Patterns ◽

Contact Interactions ◽

Solid Contact ◽

Mechatronic Systems ◽

Stick Slip ◽

Frictional Contacts

Modeling of the soft-solid frictional interactions plays an important role in many robotic and mechatronic systems design. We present a new model that characterizes the two-dimensional (2D) soft-solid contact interactions. The new computational approach integrates the LuGre dynamic friction model with the beam network structure of the soft-solid contact. The LuGre dynamic friction model uses the bristle deformation to capture the friction characteristics and dynamics, while the beam network structure represents the elastic contact interactions. We also present a model simplification to facilitate analysis of model properties. The model prediction and validation results are demonstrated with the experiments. The experimental results confirm the effectiveness of the modeling development. We further use the model to compute the influence of the normal load and sliding velocity on the stick-slip interaction patterns and properties. These results explain and provide analytical foundation for the reported experiments in the literature.

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Stick-Slip Behaviour of Seals With Respect to Time Dependent Friction Forces

Manufacturing Engineering and Materials Handling Engineering ◽

10.1115/imece2004-59586 ◽

2004 ◽

Cited By ~ 2

Author(s):

Markus Lindner ◽

Matthias Kro¨ger ◽

Karl Popp ◽

Manuel Gime´nez

Keyword(s):

Stability Analysis ◽

Time Dependent ◽

Dynamic Friction ◽

Slip Effect ◽

Stick Slip ◽

Friction Forces ◽

Seal Design

In the present paper dynamic friction processes in seals are investigated. The undesired stick-slip effect of these components under real technical conditions is analyzed. Starting with the basics of stick-slip vibrations the development of an advanced seal design with improved properties is presented that prevents stick-slip. Finally, an optimization based on the extensive but simple stability analysis is shown by an expanded theory of stick-slip simulations.

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Dynamic Friction Characteristics of Bulk Seeds Against Flat Vertical Surfaces

Transactions of the ASAE ◽

10.13031/2013.28648 ◽

1992 ◽

Vol 35 (2) ◽

pp. 665-669 ◽

Cited By ~ 6

Author(s):

D. A. Irvine ◽

D. S. Jayas ◽

M. G. Britton ◽

N. D. G. White

Keyword(s):

Dynamic Friction ◽

Friction Characteristics

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The dynamic friction characteristics of a rapidly sheared granular material applied to the motion of snow avalanches

Annals of Glaciology ◽

10.3189/s026030550001154x ◽

1993 ◽

Vol 18 ◽

pp. 215-220 ◽

Cited By ~ 2

Author(s):

J.D. Dent

Keyword(s):

Shear Layer ◽

Slip Plane ◽

Flat Surface ◽

Dynamic Friction ◽

Friction Characteristics ◽

Dynamic Friction Coefficient ◽

Dispersed Particles ◽

Number Of Layers ◽

Shear Speed ◽

Shearing Motion

A numerical simulation of simple two-dimensional shear of round uniform grains is used to investigate the dynamic friction characteristics of the layer of snow at the base of an avalanche. For steady, uniform flow on a uniform flat surface, the dynamic friction coefficient transmitted through the shear array is found as it varies with the shear speed and normal force applied to the top of the shear layer, and the properties of the particles in the shear layer.For this simple model, the flow in the shear layer is found to be independent of the total number of layers in the shear flow. A slip plane is formed along which most of the shearing motion takes places, so that the shear is confined to just two layers of particles which slide over one another. In the absence of gravity this slip plane jumps up and down randomly within the shear layer, which is otherwise composed of agitated semi-dispersed particles.

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Stick-slip and Torsional Friction Factors in Inclined Wellbores

MATEC Web of Conferences ◽

10.1051/matecconf/201814816002 ◽

2018 ◽

Vol 148 ◽

pp. 16002 ◽

Cited By ~ 1

Author(s):

Ulf Jakob F. Aarsnes ◽

Roman J. Shor

Keyword(s):

High Frequency ◽

String Model ◽

Drill String ◽

Distributed Model ◽

Dynamic Friction ◽

Stick Slip ◽

Rock Interaction ◽

Interaction Field ◽

Friction Factors ◽

Start Ups

Stick slip is usually considered a phenomenon of bit-rock interaction, but is also often observed in the field with the bit off bottom. In this paper we present a distributed model of a drill string with an along-string Coulomb stiction to investigate the effect of borehole inclination and borehole friction on the incidence of stick-slip. This model is validated with high frequency surface and downhole data and then used to estimate static and dynamic friction. A derivation of the torsional drill string model is shown and includes the along-string Coulomb stiction of the borehole acting on the string and the ‘velocity weakening’ between static and dynamic friction. The relative effects of these two frictions is investigated and the resulting drillstring behavior is presented. To isolate the effect of the along-string friction from the bit-rock interaction, field data from rotational start-ups after a connection (with bit off bottom) is considered. This high frequency surface and downhole data is then used to validate the surface and downhole behavior predicted by the model. The model is shown to have a good match with the surface and downhole behavior of two deviated wellbores for depths ranging from 1500 to 3000 meters. In particular, the model replicates the amplitude and period of the oscillations, in both the topside torque and the downhole RPM, as caused by the along-string stick slip. It is further shown that by using the surface behavior of the drill-string during rotational startup, an estimate of the static and dynamic friction factors along the wellbore can be obtained, even during stick-slip oscillations, if axial tension in the drillstring is considered. This presents a possible method to estimate friction factors in the field when off-bottom stick slip is encountered, and points in the direction of avoiding stick slip through the design of an appropriate torsional start-up procedure without the need of an explicit friction test.

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Compensation of Stick-Slip Phenomenon in an Electrical Actuator

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2003.p0398 ◽

2003 ◽

Vol 15 (4) ◽

pp. 398-405 ◽

Cited By ~ 2

Author(s):

R. Merzouki ◽

◽

J. C. Cadiou ◽

N. K. M'Sirdi

Keyword(s):

Friction Force ◽

Static Friction ◽

Adaptive Controller ◽

Nonlinear Observer ◽

Convergence To Equilibrium ◽

Dynamic Friction ◽

Slip Effect ◽

Stick Slip ◽

Electrical Actuator ◽

Slip Phenomenon

In mechanical systems involving low-speed motion, consisting of a succession of jumps and stops, as in trained wagons or manipulated robots, control usually exhibits error when the static friction force exceeds the dynamic friction force in what is known as the stick-slip effect. We developed a nonlinear observer to determine the friction force of contact during motion and to compensate for its effect. Simulation and experimental results show global convergence to equilibrium and good performance by the adaptive controller.

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