scholarly journals Frictional Sliding of Rough Surfaces Using a Quasi-static Approach to the Maxwell-slip Model

2021 ◽  
Author(s):  
Aydin Amireghbali ◽  
Demirkan Coker
Keyword(s):  
Friction Force ◽  
Lateral Position ◽  
Slip Model ◽  
Stick Slip ◽  
Initial Block ◽  
Single Mass ◽  
Static Approach ◽  
Coulomb Friction Law ◽  
Asperity Model ◽  
Mass Spring

Abstract The Maxwell-slip model consists of independent mass-spring units that are slipped by a driver over a rigid, flat, fixed substrate. In the present study, the model is interpreted as a multi-asperity model and is used to study both the friction force and the mechanisms involved in the sliding of a rough elastic surface. Coulomb friction law is assumed at the single mass-spring level. A beta probability distribution function is used to generate the initial block positions randomly. The standard deviation of the initial lateral position of the blocks is interpreted as the surface roughness. The results show that when the surface is rough enough, the sequential slip of the blocks induces a steady friction force. On the other hand, when the surface is smooth enough, the collective slip of the blocks induces stick-slip. The border between the two regimes of sliding is sharply delineated by a specific roughness value. A tribological implication is that a sufficiently rough surface may bring about steady sliding. A geophysical implication is that a geological fault segment that undergoes aseismic creep may have a rougher surface compared to its locked counterpart.

Friction-Induced Vibration Due to Mode-Coupling and Intermittent Contact Loss

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Alborz Niknam ◽  
Kambiz Farhang
Keyword(s):  
Friction Force ◽  
Mode Coupling ◽  
Degrees Of Freedom ◽  
Normal Load ◽  
Contact Stiffness ◽  
Relative Mass ◽  
Mass Motion ◽  
Stick Slip ◽  
Single Mass ◽  
Intermittent Contact

A two degrees-of-freedom (2DOFs) single mass-on-belt model is employed to study friction-induced instability due to mode-coupling. Three springs, one representing contact stiffness, the second providing lateral stiffness, and the third providing coupling between tangential and vertical directions, are employed. In the model, mass contact and separation are permitted. Therefore, nonlinearity stems from discontinuity due to dependence of friction force on relative mass-belt velocity and separation of mass-belt contact during oscillation. Eigenvalue analysis is carried out to determine the onset of instability. Within the unstable region, four possible phases that include slip, stick, separation, and overshoot are found as possible modes of oscillation. Piecewise analytical solution is found for each phase of mass motion. Then, numerical analyses are used to investigate the effect of three parameters related to belt velocity, friction coefficient, and normal load on the mass response. It is found that the mass will always experience stick-slip, separation, or both. When separation occurs, mass can overtake the belt causing additional nonlinearity due to friction force reversal. For a given coefficient of friction, the minimum normal load to prevent separation is found proportional to the belt velocity.

scholarly journals A Novel Stick-Slip Nanopositioning Stage Integrated with a Flexure Hinge-Based Friction Force Adjusting Structure

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 765
Author(s):  
Junhui Zhu ◽  
Peng Pan ◽  
Yong Wang ◽  
Sen Gu ◽  
Rongan Zhai ◽  
...  
Keyword(s):  
Friction Force ◽  
High Speed ◽  
Simulation Analysis ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Critical Role ◽  
Vertical Direction ◽  
Flexure Hinge ◽  
Stick Slip ◽  
Static Performance

The piezoelectrically-actuated stick-slip nanopositioning stage (PASSNS) has been applied extensively, and many designs of PASSNSs have been developed. The friction force between the stick-slip surfaces plays a critical role in successful movement of the stage, which influences the load capacity, dynamic performance, and positioning accuracy of the PASSNS. Toward solving the influence problems of friction force, this paper presents a novel stick-slip nanopositioning stage where the flexure hinge-based friction force adjusting unit was employed. Numerical analysis was conducted to estimate the static performance of the stage, a dynamic model was established, and simulation analysis was performed to study the dynamic performance of the stage. Further, a prototype was manufactured and a series of experiments were carried out to test the performance of the stage. The results show that the maximum forward and backward movement speeds of the stage are 1 and 0.7 mm/s, respectively, and the minimum forward and backward step displacements are approximately 11 and 12 nm, respectively. Compared to the step displacement under no working load, the forward and backward step displacements only increase by 6% and 8% with a working load of 20 g, respectively. And the load capacity of the PASSNS in the vertical direction is about 72 g. The experimental results confirm the feasibility of the proposed stage, and high accuracy, high speed, and good robustness to varying loads were achieved. These results demonstrate the great potential of the developed stage in many nanopositioning applications.

Novel Precision PZT-Driven Micropositioning Stage with Large Travel Range

2009 ◽  
Vol 407-408 ◽  
pp. 159-162
Author(s):  
Hua Wei Chen ◽  
Ichiro Hagiwara
Keyword(s):  
Dynamic Model ◽  
Piezoelectric Actuator ◽  
Dynamic Properties ◽  
Flexure Hinge ◽  
Slip Model ◽  
Stick Slip ◽  
Friction Effect ◽  
Simulation Results

One novel long-travel piezoelectric-driven linear micropositioning stage capable of moving in a stepping mode is developed. The stick-slip friction effect between flexure hinge actuation tips with a sliding stage is used to drive the stage step-by-step through an enlarged displacement of piezoelectric actuator. In order to enlarge the travel range, magnifying mechanism is optimally designed by use of flexure hinge and lever beam. Moreover, dynamic model of such stage is proposed by consideration of reset integrator stick-slip model. The simulation results show that the stage has considerable good dynamic properties.

Fractals in earthquakes

1994 ◽  
Vol 348 (1688) ◽  
pp. 449-457 ◽  
Keyword(s):  
Earthquake Prediction ◽  
Seismic Activity ◽  
Slip Model ◽  
Stick Slip ◽  
Plate Margin

Earthquake prediction is one of the most important probrems for countries on a plate margin with high seismic activity. The earthquake is a typical example of a common phenomena which has several kinds of fractal features. We introduce the ‘stick-slip model’, which can explain the fractal features of seismic phenomena to the earthquakes in Japan and discuss about the predictiblity of the destructive earthquakes.

Effects of Tip Compliance in Friction Force Microscopy

2005 ◽  
Author(s):  
William G. Conley ◽  
Arvind Raman ◽  
Charles M. Krousgrill
Keyword(s):  
Friction Force ◽  
Frictional Force ◽  
Friction Force Microscopy ◽  
Stick Slip ◽  
Force Microscopy

Friction force microscopy (FFM) enables the unprecedented measurement of friction at the nanoscale. It is known that when FFM microcantilevers are dragged across surface, the nanometer tip executes stick-slip motions as the tip “plucks” individual atoms on the surface. Tomlinson’s model is usually used to explain these effects. In what follows we investigate the effects of tip compliance on the stick-slip motions in FFM. New results are predicted describing the transition from steady sliding to single and multiple atom stick-slip. Additionally, the effect of these different motions on the average frictional force is calculated.

Uncertainty Analysis of CNC Machine Tools Based on Monte Carlo Method

2020 ◽  
Vol 900 ◽  
pp. 9-13
Author(s):  
Yunn Lin Hwang ◽  
Thi Na Ta
Keyword(s):  
Monte Carlo ◽  
Friction Coefficient ◽  
Numerical Simulations ◽  
Friction Force ◽  
System Performance ◽  
Numerical Control ◽  
Machining Accuracy ◽  
Force Model ◽  
Stick Slip ◽  
System Components

The uncertainty of mechanical system performance is strongly influenced by the properties of system components such as mass, stiffness-damping coefficient, and friction coefficient. Based on computational simulations, the system performance under uncertainty conditions can be estimated. However, the nonlinear dynamic behavior of friction is difficult to simulate in numerical simulations, this research is therefore employed a smooth stick-slip friction force model instead of the Coulomb friction force model. Monte Carlo simulation (MCS) combined with multibody dynamic (MBD) simulation is proposed to evaluate the uncertainty characteristics of the system components and stick-slip friction force between two contacting bodies. Numerical simulations applied the proposed method were performed to consider the effects of uncertainty of friction coefficient on the machining accuracy of a three axes CNC (Computer Numerical Control) machine tool.

scholarly journals Anisotropy of Graphene Nanoflake Diamond Interface Frictional Properties

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1425 ◽  
Author(s):  
Ji Zhang ◽  
Ehsan Osloub ◽  
Fatima Siddiqui ◽  
Weixiang Zhang ◽  
Tarek Ragab ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Md Simulations ◽  
Equilibrium Distance ◽  
Sliding Angle ◽  
Stick Slip ◽  
Single Crystalline ◽  
Frictional Properties ◽  
Diamond Substrate ◽  
Graphene Nanoflake

Using molecular dynamics (MD) simulations, the frictional properties of the interface between graphene nanoflake and single crystalline diamond substrate have been investigated. The equilibrium distance between the graphene nanoflake and the diamond substrate has been evaluated at different temperatures. This study considered the effects of temperature and relative sliding angle between graphene and diamond. The equilibrium distance between graphene and the diamond substrate was between 3.34 Å at 0 K and 3.42 Å at 600 K, and it was close to the interlayer distance of graphite which was 3.35 Å. The friction force between graphene nanoflakes and the diamond substrate exhibited periodic stick-slip motion which is similar to the friction force within a graphene–Au interface. The friction coefficient of the graphene–single crystalline diamond interface was between 0.0042 and 0.0244, depending on the sliding direction and the temperature. Generally, the friction coefficient was lowest when a graphene flake was sliding along its armchair direction and the highest when it was sliding along its zigzag direction. The friction coefficient increased by up to 20% when the temperature rose from 300 K to 600 K, hence a contribution from temperature cannot be neglected. The findings in this study validate the super-lubricity between graphene and diamond and will shed light on understanding the mechanical behavior of graphene nanodevices when using single crystalline diamond as the substrate.

Sign in / Sign up

Export Citation Format

Share Document