scholarly journals A model for frictional sliding instability on a heterogeneous fault

1994 ◽  
Vol 37 (6) ◽  
Author(s):  
M. Dragoni ◽  
A. Piombo

An instability of frictional sliding driven by tectonic stress is assumed to be the source of earthquakes. Empirical slip laws indicate that, under constant ambient conditions, friction depends on time, slip rate and slip history. Regular stick slip behaviour is induced by velocity weakening, a decrease of friction with slip rate. Velocity weakening is introduced into a model for a propagating Somigliana dislocation under slowly increasing shear stress in an elastic space. Two distributions of static friction are considered, characterized by asperities with sharp borders and smooth borders respectively. The instability occurs when the rate at which friction decreases becomes greater than the rate at which the applied stress must increase to produce an advance of fault slip. The possibility that this condition is fulfilled depends on the velocity dependence and on the spatial distribution of friction on the fault. In the case of sharp asperity borders, instability can take place only when some amount of slip has occurred on the fault, while this condition is not required in the case of smooth borders.

2015 ◽  
Vol 17 (4) ◽  
pp. 447-457 ◽  
Author(s):  
John Leeman ◽  
Marco Maria Scuderi ◽  
Chris Marone ◽  
Demian Saffer

2018 ◽  
Vol 113 (24) ◽  
pp. 241602 ◽  
Author(s):  
Alexander Breki ◽  
Michael Nosonovsky

Author(s):  
Xubin Song ◽  
Daniel G. Smedley

The history of the challenge of friction modeling is briefly reviewed. Then this paper focuses on the modeling and simulation study of the friction related dynamics in the Simulink® environment, because Matlab®/Simulink® are popular engineering software tools for both industry and academia. Matlab® and Simulink® are the proprietary products of MathWorks, Inc. In this paper, the static friction models are studied through Simulink® by applying fixed and variable step sizes. The comparison shows that the static Karnopp model is not only numerically tractable but also can be inclusive of the fundamental friction characteristics of both stick slip and correct friction predictions. Finally this paper presents an improved Karnopp model for clutch modeling with the use of Simulink®, and the simulation shows that this model is computationally tractable with smooth dynamics.


2008 ◽  
Vol 47-50 ◽  
pp. 246-249
Author(s):  
Min Gyu Jang ◽  
Chul Hee Lee ◽  
Seung Bok Choi

In this paper, a stick-slip compensation for the micro-positioning is presented using the statistical rough surface contact model. As for the micro-positioning structure, PZT (lead(Pb) zirconia(Zr) Titanate(Ti)) actuator is used to drive the load for precise positioning with its high resolution incorporating with the PID (Proportional Integral Derivative) control algorithm. Since the stick-slip characteristics for the micro structures are highly nonlinear and complicated, it is necessary to incorporate more detailed stick-slip model for the applications involving the high precision motion control. Thus, the elastic-plastic static friction model is used for the stick-slip compensation considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of the system for the positioning apparatus was derived from the dynamic behaviors of structural parts. Since the conventional piezoelectric actuator generates the short stroke, a bridge-type flexural hinge mechanism is introduced to amplify the linear motion range. Using the proposed smart structure, simulations under the representative positioning motion were conducted to demonstrate the micro-positioning under the stick-slip friction.


1955 ◽  
Vol 22 (2) ◽  
pp. 207-214
Author(s):  
David Sinclair

Abstract Frictional vibrations, such as stick-slip motion and automobile-brake squeal, which occur when two solid bodies are rubbed together, are analyzed mathematically and observed experimentally. The conditions studied are slow uniform motion and relatively rapid simple harmonic motion of brake lining over a cast-iron base. The equations of motion show and the observations confirm that frictional vibrations are caused primarily by an inverse variation of coefficient of friction with sliding velocity, but their form and occurrence are greatly dependent upon the dynamical constants of the mechanical system. With a constant coefficient of friction, the vibration initiated whenever sliding begins is rapidly damped out, not by the friction but by the “natural” damping of all mechanical systems. The coefficient of friction of most brake linings and other organic materials was essentially invariant with velocity, except that the static coefficient was usually greater than the sliding coefficient. Most such materials usually showed a small decrease in coefficient with increasing temperature. The persistent vibrations resulting from the excess static friction were reduced or eliminated by treating the rubbing surfaces with polar organic compounds which produced a rising friction characteristic.


2021 ◽  
pp. jgs2020-142
Author(s):  
N.M. Seymour ◽  
J.S. Singleton ◽  
R. Gomila ◽  
S.P. Mavor ◽  
G. Heuser ◽  
...  

Displacement estimates along the Atacama fault system (AFS), a crustal-scale sinistral structure that accommodated oblique convergence in the Mesozoic Coastal Cordillera arc, vary widely due to a lack of piercing points. We mapped the distribution of plutons and mylonitic deformation along the northern ∼70 km of the El Salado segment and use U-Pb geochronology to establish the slip history of the AFS. Along the eastern branch, mylonitic fabrics associated with the synkinematic ∼134–132 Ma Cerro del Pingo Complex are separated by 34–38 km, and mylonites associated with a synkinematic ∼120–119 Ma tonalite are separated by 20.5–25 km. We interpret leucocratic intrusions to be separated across the western branch by ∼16–20 km, giving a total slip magnitude of ∼54 ± 6 km across the El Salado segment. Kinematic indicators consistently record sinistral shear and zircon (U-Th)/He data suggest dip-slip motion was insignificant. Displacement occurred between ∼133–110 Ma at a slip rate of ∼2.1–2.6 km/Myr. This slip rate is low compared to modern intra-arc strike-slip faults, suggesting (1) the majority of lateral slip was accommodated along the slab interface or distributed through the forearc or (2) plate convergence rates/obliquity were significantly lower than previously modeled.Supplementary material including full U-Pb, (U-Th)/He, petrographic, and structural data with locations is available at https://doi.org/10.6084/m9.figshare.c.5262177.


Author(s):  
Pradeep L. Menezes ◽  
Kishore ◽  
Satish V. Kailas

Surface texture plays an important role as it predominantly controls the frictional behavior and transfer layer formation at the contacting surfaces. In the present investigation, basic studies were conducted using inclined pin-on-plate sliding tester to understand the role of surface texture of hard material on coefficient of friction and transfer layer formation when sliding against soft materials. HCP materials such as pure Mg and pure Zn were used as pins while 080 M40 steel was used as plate in the tests. Two surface parameters of steel plates — roughness and texture — were varied in the tests. Tests were conducted in ambient conditions under both dry and lubricated conditions. The morphologies of the worn surfaces of the pins and the formation of transfer layer on the counter surfaces were observed using a scanning electron microscope. It was observed for both the pin materials that the occurrence of stick-slip motion, the transfer layer formation and the value of coefficient of friction as well as its two components, namely, adhesion and plowing, depend primarily on surface texture. The effect of surface texture on coefficient of friction was attributed to the variation of plowing component of friction for different surfaces. Both the plowing component of friction and amplitude of stick-slip motion were highest for the surface texture that promotes plane strain conditions while these were lowest for the texture that favors plane stress conditions at the interface.


2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Luke Autry ◽  
Harris Marcus

Nitrogen implantation in Interstitial-Free steel was evaluated for its impact on metal transfer and 1100 Al rider wear. It was determined that nitrogen implantation reduced metal transfer in a trend that increased with dose; the Archard wear coefficient reductions of two orders of magnitude were achieved using a dose of 2e17 ions/cm2, 100 kV. Cold-rolling the steel and making volumetric wear measurements of the Al-rider determined that the hardness of the harder material had little impact on volumetric wear or friction. Nitrogen implantation had chemically affected the tribological process studied in two ways: directly reducing the rider wear and reducing the fraction of rider wear that ended up sticking to the ISF steel surface. The structure of the nitrogen in the ISF steel did not affect the tribological behavior because no differences in friction/wear measurements were detected after postimplantation heat treating to decompose the as-implantedε-Fe3N toγ-Fe4N. The fraction of rider-wear sticking to the steel depended primarily on the near-surface nitrogen content. Covariance analysis of the debris oxygen and nitrogen contents indicated that nitrogen implantation enhanced the tribo-oxidation process with reference to the unimplanted material. As a result, the reduction in metal transfer was likely related to the observed tribo-oxidation in addition to the introduction of nitride wear elements into the debris. The primary Al rider wear mechanism was stick-slip, and implantation reduced the friction and friction noise associated with that wear mechanism. Calculations based on the Tabor junction growth formula indicate that the mitigation of the stick-slip mechanism resulted from a reduced adhesive strength at the interface during the sticking phase.


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