scholarly journals Stick–slip motion of solids with dry friction subject to random vibrations and an external field

Nonlinearity ◽  
2010 ◽  
Vol 24 (2) ◽  
pp. 351-372 ◽  
Author(s):  
A Baule ◽  
H Touchette ◽  
E G D Cohen
Keyword(s):  
External Field ◽  
Dry Friction ◽  
Random Vibrations ◽  
Stick Slip ◽  
Stick Slip Motion ◽  
Slip Motion

Stick-slip motion of turbine blade dampers

1992 ◽  
Vol 338 (1651) ◽  
pp. 503-517 ◽  
Keyword(s):  
Turbine Blade ◽  
Dry Friction ◽  
Sheet Steel ◽  
Turbine Blades ◽  
Design Parameters ◽  
Stick Slip ◽  
Stick Slip Motion ◽  
Important Design ◽  
Small Elements ◽  
Slip Motion

Turbine blade dampers are small elements of a parabolic configuration usually fabricated from sheet steel. They are positioned loosely between the roots of turbine blades improving the damping of blade vibrations by generating dry friction from the relative motion of blades and damper. This paper presents a theoretical approach to these stick-slip vibrations and compares theory with measurements. Additionally, some design aspects of such dampers are discussed by considering the damping behaviour in relation to important design parameters.

scholarly journals Micro-Slip as a Loss of Determinacy in Dry-Friction Oscillators

2019 ◽  
Vol 29 (06) ◽  
pp. 1930015 ◽  
Author(s):  
S. Webber ◽  
M. R. Jeffrey
Keyword(s):  
Differential Equations ◽  
Dry Friction ◽  
Dynamical Theory ◽  
Stick Slip ◽  
Friction Forces ◽  
Mechanical Oscillators ◽  
The Stability ◽  
Stick Slip Motion ◽  
Friction Oscillators ◽  
Slip Motion

Dry-friction contacts in mechanical oscillators can be modeled using nonsmooth differential equations, and recent advances in dynamical theory are providing new insights into the stability and uniqueness of such oscillators. A classic model is that of spring-coupled masses undergoing stick-slip motion on a rough surface. Here, we present a phenomenon in which multiple masses transition from stick to slip almost simultaneously, but suffer a brief loss of determinacy in the process. The system evolution becomes many-valued, but quickly collapses back down to an infinitesimal set of outcomes, a sort of “micro-indeterminacy”. Though fleeting, the loss of determinacy means masses may each undergo different microscopic sequences of slipping events, before all masses ultimately slip. The microscopic loss of determinacy is visible in local changes in friction forces, and in creating a bistability of global stick-slip oscillations. If friction forces are coupled between the oscillators then the effect is more severe, as solutions are compressed instead onto two (or more) macroscopically different outcomes.

Two-dimensional stick-slip motion of Coulomb friction oscillators

2015 ◽  
Vol 230 (14) ◽  
pp. 2438-2448 ◽  
Author(s):  
M Fadaee ◽  
SD Yu
Keyword(s):  
Dry Friction ◽  
Numerical Results ◽  
Mathematical Programming Problem ◽  
Two Dimensional ◽  
State Equations ◽  
Time Step ◽  
Stick Slip ◽  
Single Body ◽  
Stick Slip Motion ◽  
Slip Motion

Two-dimensional stick-slip motion of an oscillator subjected to dry friction is investigated in this paper. The equations of motion of the non-smooth system are discretized in the time domain by means of the implicit Bozzak-Newmark scheme. The system state equations in a time step are written in the incremental displacements to model the frictional constraints in accordance with Coulomb’s law. With the help of a coordinate transformation and introduction of paired non-negative and complementary variables, the non-smooth vibration problem is reduced to a mathematical programming problem for which a numerical solution can be obtained. Numerical results for a single body oscillator under a harmonic excitation are obtained using the proposed method and compared with those in the literature; excellent agreement is achieved. The proposed method is then applied to a general two-dimensional oscillator with stiffness and viscous coupling in addition to the frictional coupling. Experiments are conducted for free vibration of a single body vibration system subjected to two-dimensional dry friction. Good agreement between the measurements and numerical results obtained using the proposed scheme is observed.

scholarly journals Bifurcation Analysis of Stick-Slip Motion of the Vibration-Driven System with Dry Friction

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Peng Li ◽  
Ziwang Jiang
Keyword(s):  
Dry Friction ◽  
Numerical Continuation ◽  
Internal Mass ◽  
Stick Slip ◽  
Sliding Bifurcation ◽  
Directional Control ◽  
Driven System ◽  
Stick Slip Motion ◽  
Two Parameter ◽  
Slip Motion

This paper is concerned with the vibration-driven system which can move due to the periodic motion of the internal mass and the dry friction; the system can be modeled as Filippov system and has the property of stick-slip motion. Different periodic solutions of stick-slip motion can be analyzed through sliding bifurcation, two-parameter numerical continuation for sliding bifurcation is carried out to get the different bifurcation curves, and the bifurcation curves divide the parameters plane into different regions which stand for different stick-slip motion of the periodic solution. Furthermore, continuations with additional condition v=0 are carried out for the directional control of the vibration-driven system in one period; the curves divide the parameter plane into different progressions.

Dynamics of stick–slip motion, Whillans Ice Stream, Antarctica

2011 ◽  
Vol 305 (3-4) ◽  
pp. 283-289 ◽  
Author(s):  
J. Paul Winberry ◽  
Sridhar Anandakrishnan ◽  
Douglas A. Wiens ◽  
Richard B. Alley ◽  
Knut Christianson
Keyword(s):  
Stick Slip ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Stick Slip Motion ◽  
Slip Motion

Dynamic simulation of stick–slip motion of a flexible solar array

2008 ◽  
Vol 16 (6) ◽  
pp. 724-735 ◽  
Author(s):  
Yasushi Kojima ◽  
Shigemune Taniwaki ◽  
Yoshiaki Okami
Keyword(s):  
Dynamic Simulation ◽  
Solar Array ◽  
Stick Slip ◽  
Stick Slip Motion ◽  
Slip Motion

scholarly journals Basal ice motion and deformation at the ice-sheet margin, West Greenland

2005 ◽  
Vol 42 ◽  
pp. 67-70 ◽  
Author(s):  
David M. Chandler ◽  
Richard I. Waller ◽  
William G. Adam
Keyword(s):  
Deformation Mode ◽  
Time Intervals ◽  
Stick Slip ◽  
Active Deformation ◽  
West Greenland ◽  
Shear Structures ◽  
Basal Ice ◽  
Ice Velocity ◽  
Stick Slip Motion ◽  
Slip Motion

AbstractMeasurements of basal ice deformation at the margin of Russell Glacier, West Greenland, have provided an opportunity to gain more insight into basal processes occurring near the margin. The basal ice layer comprises a debris-rich, heterogeneous stratified facies, overlain by a comparatively debris-poor dispersed facies. Ice velocities were obtained from anchors placed in both ice facies, at three sites under 5–15 m ice depth. Mean velocities ranged from 20 to 43 m a–1, and velocity gradients indicate high shear strain rates within the basal ice. Stick–slip motion and diurnal variations were observed during measurements at short (1–5 min) time intervals. Vertical gradients in horizontal ice velocity indicate two modes of deformation: (1) viscous deformation within the stratified ice facies, and (2) shear at the interface between the two basal ice facies. Deformation mode 1 may contribute to the folding and shear structures observed in the stratified facies. Deformation mode 2 may generate the stick–slip motion and be associated with the formation of debris bands. Active deformation close to the margin suggests that structures observed within the basal ice are only partially representative of processes occurring near the bed in areas away from the glacier margin.

Experimental Exploration of Schallamach Waves and Self-Excitation in a Belt-Drive System

2018 ◽  
Author(s):  
Yingdan Wu ◽  
Michael Varenberg ◽  
Michael J. Leamy
Keyword(s):  
Angular Velocity ◽  
Dynamic Behavior ◽  
Oscillation Amplitude ◽  
Operating Conditions ◽  
Drive System ◽  
Belt Drive ◽  
Stick Slip ◽  
Stick Slip Motion ◽  
System Inertia ◽  
Slip Motion

We study the dynamic behavior of a belt-drive system to explore the effect of operating conditions and system moment of inertia on the generation of waves of detachment (i.e., Schallamach waves) at the belt-pulley interface. A self-excitation phenomenon is reported in which frictional fluctuations serve as harmonic forcing of the pulley, leading to angular velocity oscillations which grow in time. This behavior depends strongly on operating conditions (torque transmitted and pulley speed) and system inertia, and differs between the driver and driven pulleys. A larger net torque applied to the pulley generally yields more remarkable stick-slip oscillations with higher amplitude and lower frequency. Higher driving speeds accelerate the occurrence of stick-slip motion, but have little influence on the oscillation amplitude. Contrary to our expectations, the introduction of flywheels to increase system inertia amplified the frictional disturbances, and hence the pulley oscillations. This does, however, suggest a way of facilitating their study, which may be useful in follow-on research.

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