Modeling of Friction Induced Vibration due to Third-Body Effects

2001 ◽  
Author(s):  
David S. Xu ◽  
Hooshang Heshmat
Keyword(s):  
Friction Coefficient ◽  
Normal Load ◽  
System Response ◽  
Viscous Damping ◽  
Third Body ◽  
The Third ◽  
Damping Material ◽  
Variable Friction ◽  
Semi Empirical ◽  
Friction Induced Vibration

Abstract Friction induced vibration at contact interfaces is still a big challenging problem and not well understood how to affect the high cycle fatigue (HCF) failures in gas turbine engine and other machinery. Most researchers conducted on the subject of only two bodies in contact with the Coulomb’s friction law only. In this paper, the interface friction phenomena and induced vibration are investigated by means of the improved third-body composite interface micro-slip model which includes a variable friction coefficient and a flexible contact, represented as effective stiffness and equivalent viscous damping elements. The third-body considered herein is almost always present at contacting interfaces and is comprised of generated wear debris or a soft intermediate anti-fretting coating applied to the mating surfaces. This kind of third-body can be viewed as a thin factional damping material layer to provide shear energy dissipation in order to mitigate the destructive effects of high frequency vibrations in components with highly stressed contacts. A properly engineered third-body can also play the role of both a damping material and a lubricant to decrease wear rate. For the study presented, a semi-empirical formula for the third-body powder properties was employed, depending on the experimental data and the non-linear regression approach. The experimental powder TiO2 data included density, shear strength, frictional coefficients, loss factor as a function of normal load, shear strain, speed and frequency. The results in this paper indicate that the third body semi-empirical equivalent stiffness / viscous damping representation of a flexible contact with variable friction coefficient does indeed have merit and does have influence on overall system response. It has been shown that the third body effects should be considered in the friction and damping induced vibration on the contact interfaces. Such a model may be used to assess designs and material coating approaches to counter fretting in highly stressed contacts as well as assessing the interaction of contact kinematics on HCF failures. Further experimental investigation of specified friction contact configuration of the components needs to be conducted in order to evaluate their friction characteristics and move this technology toward a practical engineering applications.

Friction Coefficient as a Macroscopic View of Local Dissipation

2007 ◽  
Vol 129 (4) ◽  
pp. 829-835 ◽  
Author(s):  
D. Richard ◽  
I. Iordanoff ◽  
Y. Berthier ◽  
M. Renouf ◽  
N. Fillot
Keyword(s):  
Friction Coefficient ◽  
Dry Friction ◽  
Three Dimensional ◽  
Third Body ◽  
The Third ◽  
Dynamic Friction Coefficient ◽  
Approaches To Study ◽  
Set Up ◽  
Method Approach ◽  
Simple Interaction

This paper presents an overview of a discrete element method approach to dry friction in the presence of a third body. Three dimensional computer simulations have been carried out to show the influence of the third body properties (and more specifically their adhesion) on friction coefficient and profiles of dissipated power. Simple interaction laws and a cohesive contact are set up to uncouple the key parameters governing the contact rheology. The model is validated through a global energy balance. As it is shown that dynamic friction coefficient can be explained only in terms of local energy dissipation, this work also emphasizes the fact that mechanism effects and third body rheology have important consequences on the energy generation and dissipation field. Therefore, asymmetries can arise and the surface temperature of first bodies can be significantly different even for the same global friction coefficient value. Such investigations highlight the fact that friction coefficient cannot be considered in the same way at the mechanism scale as at the contact scale where the third body plays a non-negligible role, although it has been neglected for years in thermal approaches to study of surfaces in contact.

scholarly journals Enhanced Frictional Properties of NiO-based Nanocomposites With the Addition of GDC

2021 ◽  
Author(s):  
Jooho Park ◽  
Minwoo Ahn ◽  
Seungwoo Han ◽  
Wonyoung Lee ◽  
YoungZe Lee
Keyword(s):  
Grain Size ◽  
Synergetic Effect ◽  
Wear Particle ◽  
Tribological Performance ◽  
Matrix Composites ◽  
Third Body ◽  
Variable Loading ◽  
Frictional Properties ◽  
The Third ◽  
Friction Induced Vibration

Abstract The tribological performance and friction-induced vibration of Gd0.2-Ce0.8O1.9 (GDC) reinforced nickel oxide (NiO) metal matrix composites prepared via sintering on the tribological performance, as well as friction induced vibration were investigated. Compared to pure NiO, the composites exhibit improved mechanical properties, such as a relatively high dislocation density, hardness and small grain size. The results show that GDC-reinforced NiO nanocomposites feature improved tribological performance and can suppress the occurrence of friction-induced vibration under variable loading conditions. Furthermore, the generated acceleration can be suppressed by wear particles generated during the friction process, acting as the third body at the contact interface. As a result, the addition of GDC reduces the grain size of the composite, increases hardness, and improves tribological properties through the synergetic effect of the solid lubricating action of NiO and the role of the third body of the wear particle.

Properties Analysis of Disk Spring with Effects of Asymmetric Variable Friction

2021 ◽  
Author(s):  
Renzhen Chen ◽  
Xiaopeng Li ◽  
Jinchi Xu ◽  
Zemin Yang ◽  
Hexu Yang
Keyword(s):  
Friction Coefficient ◽  
Vibration Isolation ◽  
Normal Load ◽  
Static Friction ◽  
Primary Objective ◽  
Friction Model ◽  
Computational Accuracy ◽  
Static Friction Coefficient ◽  
Disk Spring ◽  
Variable Friction

The primary objective of this fundamental research is to investigate the mechanical properties of the disk spring when the friction at the contact edges is asymmetric and varies with the load. The contact mechanics study shows that the static friction and static friction coefficient on fractal surfaces change depending on the normal load. In this paper, a fractal contact model based on the W-M function is used to explore the connection between the static friction and the normal load. Subsequently, taking into account the asymmetry of the contact surface at the edge, the variable static friction coefficient is brought into the existing model to obtain an improved static model of the disk spring. Different fractal dimensions, frictional states and free heights are considered under quasi-static loading condition, the relative errors between this paper and the method using Coulomb friction are also calculated, and experimental validation was performed. The static stiffness and force hysteresis of the disk spring for different forms of asymmetric variable friction are discussed. It is shown that using the variable friction model can improve the computational accuracy of the disk spring model under small loads and help to improve the design and control accuracy of preload and vibration isolation equipment using the disk spring as a component.

Friction Coefficient as a Macroscopic View of Local Dissipation

2007 ◽  
Author(s):  
I. Iordanoff ◽  
D. Richard ◽  
M. Renouf ◽  
Y. Berthier
Keyword(s):  
Friction Coefficient ◽  
Dry Friction ◽  
Three Dimensional ◽  
Global Scale ◽  
Contact Interface ◽  
Third Body ◽  
The Third ◽  
Dynamic Friction Coefficient ◽  
Set Up ◽  
Method Approach

This paper presents an overview of a Discrete Element Method approach used to study the dry friction (global scale) taking into account local discontinuity with the presence of third body at the contact interface. Three dimensional computer simulations have been carried out to show the influence of the third body properties (and more specifically its adhesion) on the resulting friction coefficient as well as the dissipated power profiles. The physics of the interface is described by a simple cohesive contact law which is set up to uncouple the key parameters governing the contact rheology. The model is validated through a global energy balance. As it is shown that dynamic friction coefficient can be explained in term of local energy dissipation, the work also emphasizes the fact that mechanism effects and third body rheology have important consequences on the energy generation and dissipation field. The friction coefficient cannot be considered the same way at the mechanism scale than at the contact one where the third body plays a non-negligible role despite the fact that it has been neglected for years in thermal approaches of the contact.

Correlations between third body evolution and tribological performance of copper-matrix friction material under abrasive paper interference conditions

2017 ◽  
Vol 232 (6) ◽  
pp. 711-721 ◽  
Author(s):  
Linlin Su ◽  
Fei Gao ◽  
Hualong Tao ◽  
Xiaoming Han ◽  
Rong Fu
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Normal Load ◽  
High Surface ◽  
Copper Matrix ◽  
Friction Material ◽  
Third Body ◽  
Friction Mechanism ◽  
Pin On Disc ◽  
Abrasive Paper

The influence of the degree of morphological variances of third body on the friction coefficient is a foundational question for understanding the friction mechanism. The correlations between the composition and morphology of third body as well as the surface roughness and the friction coefficient of copper-matrix friction material were investigated using a pin-on-disc tribometer by a method of interface interference caused by various grit size abrasive papers by grinding the friction surface during friction. Friction tests were conducted under friction speeds of 200–800 r/min at a normal load of 0.5 MPa. The results indicate that the friction coefficients increase under dry abrasive paper interference condition. It is generally 0.07–0.09 higher than the noninterference case. Large particle sizes of abrasive paper interference causes the change in the morphology of third body. More specifically, high surface roughness caused by plowing of coarse abrasive paper interference is the main cause for high friction coefficient. This phenomenon is weakened with the increase in speed. And small particle size of abrasive paper interference induces the change in the composition and distribution of third body due to fine SiC particles grinding and embedding into the friction interface. These changes increase the hard spots contact area, exacerbate the abrasive wear at all speeds, leading to a higher friction coefficient.

Study on the Lubrication and Antifriction Mechanism of Low Frictional Self-Lubricating Wear-Resisting Coating

2011 ◽  
Vol 339 ◽  
pp. 477-482 ◽  
Author(s):  
Yun Cai Zhao ◽  
Shu Feng Huang ◽  
Xiao Mei Liu
Keyword(s):  
Friction Coefficient ◽  
Friction Factor ◽  
Room Temperature ◽  
Abrasive Particle ◽  
Surface Texturing ◽  
Laser Remelting ◽  
Third Body ◽  
The Third ◽  
Abrasion Loss ◽  
Supersonic Plasma

This paper is about the lubricating wear-resisting coating KF301/WS2 and round pit texturing modified coating KF301/WS2 which are prepared by supersonic plasma spraying, laser remelting and surface texturing technology, tribological characteristics of two kinds of coatings are studied under room temperature, according to this, it is discussed for lubrication antifriction mechanism. The research shows: round pit texture has a certain influence on friction factor of coating’s surface and abrasion loss. Friction coefficient of untextured surface is about 0.0138 in the initial stages, while friction coefficient of round pit texture is about 0.01, compared with the former, the latter decreases 27%; when wear time reaches to 1 hour, abrasion loss of untextured surface is 0.0026mg, while abrasion loss of round pit texture is about 0.013mg, compared with the former, the latter decreases 50%. The lubricant antifriction performance of round pit texture is higher than untextured surface, this is because friction coefficient of coating is decreased as the change of the third-body bed, and round pit micro moulding can collect abrasive particle, decreasing the influence of abrasive particle.

scholarly journals Shear thinning in non-Brownian suspensions explained by variable friction between particles

2018 ◽  
Vol 860 ◽  
pp. 682-710 ◽  
Author(s):  
Laurent Lobry ◽  
Elisabeth Lemaire ◽  
Frédéric Blanc ◽  
Stany Gallier ◽  
François Peters
Keyword(s):  
Shear Stress ◽  
Friction Coefficient ◽  
Volume Fraction ◽  
Normal Load ◽  
Shear Thinning ◽  
Particle Volume ◽  
Normal Contact ◽  
Force Coupling ◽  
Applied Shear Stress ◽  
Variable Friction

We propose to explain shear-thinning behaviour observed in most concentrated non-Brownian suspensions by variable friction between particles. Considering the low magnitude of the forces experienced by the particles of suspensions under shear flow, it is first argued that rough particles come into solid contact through one or a few asperities. In such a few-asperity elastic–plastic contact, the friction coefficient is expected not to be constant but to decrease with increasing normal load. Simulations based on the force coupling method and including such a load-dependent friction coefficient are performed for various particle volume fractions. The results of the numerical simulations are compared to viscosity measurements carried out on suspensions of polystyrene particles ($40~\unicode[STIX]{x03BC}\text{m}$in diameter) dispersed in a Newtonian silicon oil. The agreement is shown to be satisfactory. Furthermore, the comparison between the simulations conducted either with a constant or a load-dependent friction coefficient provides a model for the shear-thinning viscosity. In this model the effective friction coefficient$\unicode[STIX]{x1D707}^{eff}$is specified by the effective normal contact force which is simply proportional to the bulk shear stress. As the shear stress increases,$\unicode[STIX]{x1D707}^{eff}$decreases and the jamming volume fraction increases, leading to the reduction of the viscosity. Finally, using this model, we show that it is possible to evaluate the microscopic friction coefficient for each applied shear stress from the rheometric measurements.

scholarly journals Analysis of Sheet Metal Forming (Warm Stamping Process): A Study of the Variable Friction Coefficient on 6111 Aluminum Alloy

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1189
Author(s):  
Shasha Dou ◽  
Xiaoping Wang ◽  
Jason Xia ◽  
Lisa Wilson
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Normal Load ◽  
Thickness Distribution ◽  
Simulation Software ◽  
Spring Back ◽  
Sliding Speed ◽  
Test Measurement ◽  
Variable Friction

Aluminum alloy materials have been widely used in automobile, aerospace and other fields because of their low density, high specific strength and corrosion resistance. The process of the warm forming of aluminum alloy improves the formability of aluminum alloy sheets, reduces the deformation resistance and spring-back and improves the forming accuracy and quality of parts. For these reasons, it is frequently used. In this work, the effects of temperature, sliding speed and normal load on the friction coefficient of 6111 aluminum alloy were studied by using a CFT-I (Equipment Type) friction tester under boundary lubrication conditions. The surface morphology of the sample after the friction test was observed by optical microscopy. The results show that the surface quality of aluminum alloy is better at 200 °C, which was used as the temperature in the experiments. According to the test measurement results, the friction coefficient increases with the increase in temperature and decreases with the increase in sliding speed and normal load. Variable friction coefficient models of sliding speed and normal load were established. Using the optimal parameter combination as the simulation parameter, the established variable friction coefficient models were input into numerical simulation software, and two sets of comparative simulations were established. The thickness distribution of the sheet material obtained through the simulation was compared with the actual test measurement. Further verification was carried out through the amount of spring-back. The results show that the thickness distribution and spring-back of the sheet obtained by the variable friction coefficient model are closer to the actual measurements (the error of the spring-back angle decreased from more than 20% to less than 10%), which verifies the reliability and accuracy of the variable friction coefficient model.

scholarly journals Temperature Effects on the Friction and Wear Behaviors of SiCp/A356 Composite against Semimetallic Materials

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Like Pan ◽  
Jianmin Han ◽  
Zhiyong Yang ◽  
Jialin Wang ◽  
Xiang Li ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Debris ◽  
Friction And Wear ◽  
Brake Disc ◽  
Third Body ◽  
Braking Performance ◽  
The Third ◽  
Braking Process ◽  
Disc Configuration ◽  
Worn Surface

Due to the low density and high temperature resistance, the SiCp/A356 composites have great potential for weight reduction and braking performance using the brake disc used in trains and automobiles. But the friction coefficient and braking performance are not stable in the braking process because of temperature rising. In this paper, friction and wear behaviors of SiCp/A356 composite against semimetallic materials were investigated in a ring-on-disc configuration in the temperature range of 30°C to 300°C. Experiments were conducted at a constant sliding speed of 1.4 m/s and an applied load of 200 N. Worn surface, subsurface, and wear debris were also examined by using SEM and EDS techniques. The third body films (TBFs) lubricated wear transferred to the third body abrasive wear above 200°C, which was a transition temperature. The friction coefficient decreased and weight of semimetallic materials increased with the increase of temperature and the temperature had almost no effect on the weight loss of composites. The dominant wear mechanism of the composites was microploughing and slight adhesion below 200°C, while being controlled by cutting grooves, severe adhesion, and delamination above the 200°C.

Effect of Graphite Content on the Tribological Performance of Copper-Matrix Composites Under Different Friction Speeds

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Han Xiao-Ming ◽  
Gao Fei ◽  
Su Lin-Lin ◽  
Fu Rong ◽  
Zhang En
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
High Speed ◽  
Copper Matrix ◽  
Tribological Performance ◽  
Matrix Composites ◽  
Third Body ◽  
H13 Steel ◽  
Copper Matrix Composites ◽  
The Third

The effect of graphite (Gr) content on tribological performance of copper-matrix composites against H13 steel was investigated using a pin-on-disk test in the range of 3.14–47.1 m/s. The composites with different weight fractions of Gr (up to 18%) were fabricated by powder metallurgy technique. The results showed that the friction coefficient and wear rate generally decreased with the increase in Gr content. However, the friction coefficient and wear rate differ at various speeds. At 200 and 500 r/min, the friction coefficient and wear rate kept lower with the increase in Gr content, because the third body of Cu–Al–3%Gr specimen had strong fluidity and plasticity. By contrast, the particle third body of Cu–Al–12%Gr specimen, which contained higher content of Gr, could roll easily. Increased Gr feeding to the third body was reasonable for the decreasing of friction coefficient and wear with the increasing of the amount of Gr content at the speed in the range of 1000–2000 r/min. Under the high-speed, the friction coefficient showed slight change because the friction temperature induced all the third bodies to extend and flow effortlessly without componential influence. However, wear decreased significantly because the third body possessed more metal, which favored attachment to the counter disk.

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