Comparison of Four Friction Models: Feature Prediction

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Yun-Hsiang Sun ◽  
Tao Chen ◽  
Christine Qiong Wu ◽  
Cyrus Shafai
Keyword(s):  
Numerical Model ◽  
Viscous Friction ◽  
Friction Model ◽  
Dynamic Features ◽  
Numerical Predictions ◽  
Wide Range ◽  
Model Predictions ◽  
Friction Models ◽  
Parameter Identifications ◽  
Model Structures

In this paper, we provide not only key knowledge for friction model selection among candidate models but also experimental friction features compared with numerical predictions reproduced by the candidate models. A motor-driven one-dimensional sliding block has been designed and fabricated in our lab to carry out a wide range of control tasks for the friction feature demonstrations and the parameter identifications of the candidate models. Besides the well-known static features such as break-away force and viscous friction, our setup experimentally demonstrates subtle dynamic features that characterize the physical behavior. The candidate models coupled with correct parameters experimentally obtained from our setup are taken to simulate the features of interest. The first part of this work briefly introduces the candidate friction models, the friction features of interest, and our experimental approach. The second part of this work is dedicated to the comparisons between the experimental features and the numerical model predictions. The discrepancies between the experimental features and the numerical model predictions help researchers to judge the accuracy of the models. The relation between the candidate model structures and their numerical friction feature predictions is investigated and discussed. A table that summarizes how to select the most optimal friction model among a variety of engineering applications is presented at the end of this paper. Such comprehensive comparisons have not been reported in previous literature.

scholarly journals Study on Friction in Automotive Shock Absorbers Part 1: Friction Simulation Using a Dynamic Friction Model in the Contact Zone of an FEM Model

Vehicles ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 212-232
Author(s):  
Ludwig Herzog ◽  
Klaus Augsburg
Keyword(s):  
Ride Comfort ◽  
Viscous Friction ◽  
Simulation Method ◽  
Friction Model ◽  
Model Parameters ◽  
Dynamic Friction ◽  
Friction Modeling ◽  
Shock Absorbers ◽  
Operation Conditions ◽  
Wide Range

The important change in the transition from partial to high automation is that a vehicle can drive autonomously, without active human involvement. This fact increases the current requirements regarding ride comfort and dictates new challenges for automotive shock absorbers. There exist two common types of automotive shock absorber with two friction types: The intended viscous friction dissipates the chassis vibrations, while the unwanted solid body friction is generated by the rubbing of the damper’s seals and guides during actuation. The latter so-called static friction impairs ride comfort and demands appropriate friction modeling for the control of adaptive or active suspension systems. In this article, a simulation approach is introduced to model damper friction based on the most friction-relevant parameters. Since damper friction is highly dependent on geometry, which can vary widely, three-dimensional (3D) structural FEM is used to determine the deformations of the damper parts resulting from mounting and varying operation conditions. In the respective contact zones, a dynamic friction model is applied and parameterized based on the single friction point measurements. Subsequent to the parameterization of the overall friction model with geometry data, operation conditions, material properties and friction model parameters, single friction point simulations are performed, analyzed and validated against single friction point measurements. It is shown that this simulation method allows for friction prediction with high accuracy. Consequently, its application enables a wide range of parameters relevant to damper friction to be investigated with significantly increased development efficiency.

Ensemble Grey and Black-box Nonlinear System Identification of a Positioning System

2020 ◽  
Author(s):  
Walisson Chaves Ferreira Pinto ◽  
Helon Vicente Hultmann Ayala
Keyword(s):  
Nonlinear System ◽  
Nonlinear System Identification ◽  
Viscous Friction ◽  
Black Box ◽  
Friction Model ◽  
Model Construction ◽  
Ensemble Model ◽  
Positioning System ◽  
Friction Models ◽  
Coulomb Model

In this work, grey and black-box approaches are used in order to model a electromechanical positioning system (EMPS). An ensemble model is then constructed by combining these two approaches, by using the predictions of both models in order to generate an improved estimated output. Four friction models, in their symmetric and asymmetric versions,namely (i) Coulomb model with finite slope at zero velocity and viscous friction, (ii) Coulomb model with viscous friction, (iii) Tustin friction model, (iv) Coulomb model with viscous friction and Stribeck effect were used to describe the dynamic behavior of the EMPS. The results have shown that the combination of grey and black-box models was able to perform better than the grey-box model and that the proposed friction models are also able to improve the relativeerror. This encourages further research on the application of the concept of ensemble model construction from machine learning to the nonlinear system identication context towards more accurate model construction.

3D Numerical Simulation and PEPT Experimental Investigation of Pressurized Gas-Solid Fluidized Bed Hydrodynamic

2009 ◽  
Author(s):  
P. Fede ◽  
G. Moula ◽  
A. Ingram ◽  
T. Dumas ◽  
O. Simonin
Keyword(s):  
Numerical Model ◽  
Fluidized Bed ◽  
Particle Velocity ◽  
Particle Trajectory ◽  
Wall Region ◽  
3 Dimensional ◽  
The Core ◽  
Numerical Predictions ◽  
Model Predictions ◽  
Good Agreement

The present paper is dedicated to numerical and experimental study of the hydrodynamic of a non-reactive isothermal pressurized fluidized bed. Experimental data have been obtained using PEPT technique allowing to track a particle trajectory inside a dense fluidized bed. A specific post-processing approach has been developed to compute the Eulerian time-averaged particle velocity field. The comparison with 3-dimensional numerical model predictions shows a good agreement in the core of the fluidized bed. In contrast, in the near wall region the numerical model overestimate the downward particle velocity. The modification of particle phase wall boundary condition improves the numerical predictions.

scholarly journals Estimating Friction Parameters in Reaction Wheels for Attitude Control

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Valdemir Carrara ◽  
Hélio Koiti Kuga
Keyword(s):  
Attitude Control ◽  
Deterministic Model ◽  
High Reliability ◽  
Viscous Friction ◽  
Static Friction ◽  
Friction Model ◽  
Artificial Satellites ◽  
Wide Range ◽  
The Stability ◽  
Friction Parameters

The ever-increasing use of artificial satellites in both the study of terrestrial and space phenomena demands a search for increasingly accurate and reliable pointing systems. It is common nowadays to employ reaction wheels for attitude control that provide wide range of torque magnitude, high reliability, and little power consumption. However, the bearing friction causes the response of wheel to be nonlinear, which may compromise the stability and precision of the control system as a whole. This work presents a characterization of a typical reaction wheel of 0.65 Nms maximum angular momentum storage, in order to estimate their friction parameters. It used a friction model that takes into account the Coulomb friction, viscous friction, and static friction, according to the Stribeck formulation. The parameters were estimated by means of a nonlinear batch least squares procedure, from data raised experimentally. The results have shown wide agreement with the experimental data and were also close to a deterministic model, previously obtained for this wheel. This model was then employed in a Dynamic Model Compensator (DMC) control, which successfully reduced the attitude steady state error of an instrumented one-axis air-bearing table.

Friction in Double Action Extrusion

2009 ◽  
Vol 424 ◽  
pp. 153-160 ◽  
Author(s):  
Li Liang Wang ◽  
Jie Zhou ◽  
Jurek Duczczyk
Keyword(s):  
Coulomb Friction ◽  
Fem Simulation ◽  
Friction Model ◽  
Extrusion Force ◽  
Testing Method ◽  
Friction Factors ◽  
Wide Range ◽  
Shear Friction ◽  
Friction Models ◽  
Coulomb Friction Model

A novel extrusion testing method, double action extrusion (DAE), to highlight the effect of friction at the die bearing in aluminum extrusion was developed. It was found that the lengths of the extrudates and extrusion force were indeed sensitive to the die bearing length and thus to the friction. FEM simulations of DAE were carried out to evaluate the shear and Coulomb friction models over a wide range of friction factors/coefficients from 0.2 to 1. The full sticking friction appeared to represent the interfacial contact between hot aluminum and die the best. The friction factor values in the shear friction model over a range of 0.3 to 0.6 commonly used to describe the contact at the billet-die interface in FEM simulation appeared to be too low. The comparison between the experimental and simulation results indicated that the shear friction model at m = 1 predicted the extrusion force the best, while the Coulomb friction model at µ = 1 predicted the extrudate lengths the best. Of the existing friction models and friction factors/coefficients, it is recommended to use the shear friction model at m = 1 to describe the friction at the billet-die interface in FEM simulation.

Vibration Transmission Characteristics of Periodic Composite Pipeline Considering Friction Coupling Effect

2021 ◽  
Author(s):  
Qingna Zeng ◽  
Donghui Wang ◽  
Fenggang Zang ◽  
Yixiong Zhang
Keyword(s):  
Energy Dissipation ◽  
Coupling Effect ◽  
Viscous Friction ◽  
Friction Model ◽  
Pass Band ◽  
Pipeline System ◽  
Frequency Range ◽  
Band Frequency ◽  
Periodic Composite ◽  
Friction Models

Abstract In this paper, transmission characteristic of periodic composite pipeline is investigated for axial vibration, focusing on friction coupling effect. A novel transfer matrix method is developed to calculate band gap structures (BGs) with the consideration of different forms of viscous friction. Frequency response function for finite periods is obtained and shows good consistency with BGs for infinite periods. The energy dissipation caused by viscous friction exists in the entire frequency range, as friction coupling is always distributed along the pipe element. Meanwhile, the attenuation intensity is relatively small compared with that induced by Bragg scattering mechanism. Therefore, viscous friction is not affecting the overall trend of BGs, only exhibiting certain attenuation in pass band frequency range. The effect of kinematic viscous coefficients on axial BGs are systematically examined in different friction models. Attenuation intensity goes up with increasing kinematic viscous coefficients, in addition, energy dissipation caused by frequency dependent friction model is generally higher than that of steady state friction condition. Moreover, frictional dissipation shows more sensitivity to high frequency. The research in this paper enriches fluid structure interaction theory of pipe element, which is also expected to be helpful in controlling the dynamical behaviors of pipeline system conveying fluid.

scholarly journals Tire/Road Rolling Resistance Modeling: Discussing the Surface Macrotexture Effect

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 538
Author(s):  
Malal Kane ◽  
Ebrahim Riahi ◽  
Minh-Tan Do
Keyword(s):  
Slip Rate ◽  
Rolling Resistance ◽  
Friction Model ◽  
Slip Rates ◽  
Wide Range ◽  
Road Surfaces ◽  
Profile Depth ◽  
Experimental Rolling ◽  
Resistance Modeling ◽  
Pavement Friction

This paper deals with the modeling of rolling resistance and the analysis of the effect of pavement texture. The Rolling Resistance Model (RRM) is a simplification of the no-slip rate of the Dynamic Friction Model (DFM) based on modeling tire/road contact and is intended to predict the tire/pavement friction at all slip rates. The experimental validation of this approach was performed using a machine simulating tires rolling on road surfaces. The tested pavement surfaces have a wide range of textures from smooth to macro-micro-rough, thus covering all the surfaces likely to be encountered on the roads. A comparison between the experimental rolling resistances and those predicted by the model shows a good correlation, with an R2 exceeding 0.8. A good correlation between the MPD (mean profile depth) of the surfaces and the rolling resistance is also shown. It is also noticed that a random distribution and pointed shape of the summits may also be an inconvenience concerning rolling resistance, thus leading to the conclusion that beyond the macrotexture, the positivity of the texture should also be taken into account. A possible simplification of the model by neglecting the damping part in the constitutive model of the rubber is also noted.

scholarly journals Developments in Modelling Bone Screwing

2020 ◽  
Vol 6 (3) ◽  
pp. 111-114
Author(s):  
Jack Wilkie ◽  
Paul D. Docherty ◽  
Knut Möller
Keyword(s):  
Material Properties ◽  
Frictional Coefficient ◽  
Viscous Friction ◽  
Model Parameters ◽  
General Shape ◽  
Bone Material ◽  
Bone Material Properties ◽  
Modelling Methodology ◽  
Recorded Data ◽  
Friction Models

AbstractINTRODUCTION: A torque-rotation model of the bone-screwing process has been proposed. Identification of model parameters using recorded data could potentially be used to determine the material properties of bone. These properties can then be used to recommend tightening torques to avoid over or under-tightening of bone screws. This paper improves an existing model to formulate it in terms of material properties and remove some assumptions. METHOD: The modelling methodology considers a critical torque, which is required to overcome friction and advance the screw into the bone. Below this torque the screw may rotate with elastic deformation of the bone tissue, and above this the screw moves relative to the bone, and the speed is governed by a speed-torque model of the operator’s hand. The model is formulated in terms of elastic modulus, ultimite tensile strength, and frictional coefficient of the bone and the geometry of the screw and hole. RESULTS: The model output shows the speed decreasing and torque increasing as the screw advances into the bone, due to increasing resistance. The general shape of the torque and speed follow the input effort. Compared with the existing model, this model removes the assumption of viscous friction, models the increase in friction as the screw advances into the bone, and is directly in terms of the bone material properties. CONCLUSION: The model presented makes significant improvements on the existing model. However it is intended for use in parameter identification, which was not evaluated here. Further simulation and experimental validation is required to establish the accuracy and fitness of this model for identifying bone material properties.

Near-Wall Microlayer Evaporation Analysis and Experimental Study of Nucleate Pool Boiling on Inclined Surfaces

1998 ◽  
Vol 120 (3) ◽  
pp. 641-653 ◽  
Author(s):  
G. F. Naterer ◽  
W. Hendradjit ◽  
K. J. Ahn ◽  
J. E. S. Venart
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heating Surface ◽  
Nucleate Boiling ◽  
Inclined Surfaces ◽  
Wide Range ◽  
Model Predictions ◽  
Microlayer Evaporation ◽  
Near Wall

Boiling heat transfer from inclined surfaces is examined and an analytical model of bubble growth and nucleate boiling is presented. The model predicts the average heat flux during nucleate boiling by considering alternating near-wall liquid and vapor periods. It expresses the heat flux in terms of the bubble departure diameter, frequency and duration of contact with the heating surface. Experiments were conducted over a wide range of upward and downward-facing surface orientations and the results were compared to model predictions. More active microlayer agitation and mixing along the surface as well as more frequent bubble sweeps along the heating surface provide the key reasons for more effective heat transfer with downward facing surfaces as compared to upward facing cases. Additional aspects of the role of surface inclination on boiling dynamics are quantified and discussed.

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