scholarly journals Dry friction in the Frenkel-Kontorova-Tomlinson model: dynamical properties

1997 ◽  
Vol 104 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Michael Weiss ◽  
Franz-Josef Elmer
Keyword(s):  
Dry Friction ◽  
Tomlinson Model ◽  
Dynamical Properties

Dry friction in the Frenkel-Kontorova-Tomlinson model: Static properties

1996 ◽  
Vol 53 (11) ◽  
pp. 7539-7549 ◽  
Author(s):  
Michael Weiss ◽  
Franz-Josef Elmer
Keyword(s):  
Dry Friction ◽  
Static Properties ◽  
Tomlinson Model

Primary Resonance of Dry-Friction Oscillator With Fractional-Order Proportional-Integral-Derivative Controller of Velocity Feedback

2016 ◽  
Vol 11 (5) ◽  
Author(s):  
Yongjun Shen ◽  
Jiangchuan Niu ◽  
Shaopu Yang ◽  
Sujuan Li
Keyword(s):  
Analytical Solution ◽  
Fractional Order ◽  
Dry Friction ◽  
Primary Resonance ◽  
Proportional Integral Derivative ◽  
Velocity Feedback ◽  
Integer Order ◽  
Proportional Integral ◽  
Friction Oscillator ◽  
Dynamical Properties

The classical mass-on-moving-belt model describing friction-induced vibration is studied. The primary resonance of dry-friction oscillator with fractional-order PID (FOPID) controller of velocity feedback is investigated by Krylov–Bogoliubov–Mitropolsky (KBM) asymptotic method, and the approximately analytical solution is obtained. The effects of the parameters in FOPID controller on dynamical properties are characterized by five equivalent parameters. Those equivalent parameters could distinctly illustrate the effects of the parameters in FOPID controller on the dynamical response. The effects of dry friction on the dynamical properties are characterized in the form of the equivalent linear damping and nonlinear damping. The amplitude-frequency equation for steady-state solution associated with the stability condition is also studied. A comparison of the analytical solution with the numerical results is fulfilled, and their satisfactory agreement verifies the correctness of the approximately analytical results. Finally, the effects of the coefficients and orders in FOPID controller on the amplitude-frequency curves are analyzed, and the control performances of FOPID and traditional integer-order proportional-integral-derivative (PID) controllers are compared. The comparison results show that FOPID controller is better than traditional integer-order PID controller for controlling the primary resonance of dry-friction oscillator, when the coefficients of the two controllers are the same. This presents theoretical basis for scholars and engineers to design similar fractional-order controlled system.

From the Oort cloud to Halley-type comets

1999 ◽  
Vol 173 ◽  
pp. 327-338 ◽  
Author(s):  
J.A. Fernández ◽  
T. Gallardo
Keyword(s):  
Total Population ◽  
Complex Function ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Capture Process ◽  
Influx Rate ◽  
Short Period ◽  
Dynamical Properties ◽  
Orbital Periods ◽  
Probability Of Capture

AbstractThe Oort cloud probably is the source of Halley-type (HT) comets and perhaps of some Jupiter-family (JF) comets. The process of capture of Oort cloud comets into HT comets by planetary perturbations and its efficiency are very important problems in comet ary dynamics. A small fraction of comets coming from the Oort cloud − of about 10−2− are found to become HT comets (orbital periods < 200 yr). The steady-state population of HT comets is a complex function of the influx rate of new comets, the probability of capture and their physical lifetimes. From the discovery rate of active HT comets, their total population can be estimated to be of a few hundreds for perihelion distancesq <2 AU. Randomly-oriented LP comets captured into short-period orbits (orbital periods < 20 yr) show dynamical properties that do not match the observed properties of JF comets, in particular the distribution of their orbital inclinations, so Oort cloud comets can be ruled out as a suitable source for most JF comets. The scope of this presentation is to review the capture process of new comets into HT and short-period orbits, including the possibility that some of them may become sungrazers during their dynamical evolution.

Dynamical properties of highly entangled polyalkylmethacrylate solutions : A comparative study

2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-321-Pr7-324
Author(s):  
V. Villari ◽  
A. Faraone, ◽  
S. Magazù, ◽  
G. Maisano ◽  
R. Ponterio
Keyword(s):  
Comparative Study ◽  
Dynamical Properties

Output trajectory tracking for mechanical systems with dry friction: A DPC approach

1997 ◽  
Author(s):  
D. von Wissel ◽  
R. Nikoukhah ◽  
F. Delebecque ◽  
P.-A. Bliman ◽  
M. Soline
Keyword(s):  
Trajectory Tracking ◽  
Dry Friction ◽  
Mechanical Systems ◽  
Output Trajectory

Pseudo-Anosov Theory

2017 ◽  
Author(s):  
Benson Farb ◽  
Dan Margalit
Keyword(s):  
Braid Groups ◽  
Intersection Numbers ◽  
Branched Covers ◽  
Algebraic Integers ◽  
Dehn Twists ◽  
Mapping Classes ◽  
Dynamical Properties

This chapter focuses on the construction as well as the algebraic and dynamical properties of pseudo-Anosov homeomorphisms. It first presents five different constructions of pseudo-Anosov mapping classes: branched covers, constructions via Dehn twists, homological criterion, Kra's construction, and a construction for braid groups. It then proves a few fundamental facts concerning stretch factors of pseudo-Anosov homeomorphisms, focusing on the theorem that pseudo-Anosov stretch factors are algebraic integers. It also considers the spectrum of pseudo-Anosov stretch factors, along with the special properties of those measured foliations that are the stable (or unstable) foliations of some pseudo-Anosov homeomorphism. Finally, it describes the orbits of a pseudo-Anosov homeomorphism as well as lengths of curves and intersection numbers under iteration.

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