scholarly journals Effects of hydraulic oil and lubricant additives on dynamic friction properties under various reciprocating sliding conditions

Friction ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 471-480
Author(s):  
Shinji Kato ◽  
Shinya Sasaki
Keyword(s):  
Shock Absorber ◽  
Dynamic Friction ◽  
Additive Concentration ◽  
Reciprocating Motion ◽  
Friction Behavior ◽  
Friction Characteristics ◽  
Reciprocating Sliding ◽  
Hydraulic Oil ◽  
Additive Formulation ◽  
Zinc Dithiophosphate

Abstract The friction characteristics of a shock absorber are very complex because the reciprocating motion is not always identical. In this study a device was developed and used to analyze the dynamic friction characteristics under various reciprocating sliding conditions to determine the sliding materials and hydraulic oils that improve the shock absorber performance. This study describes the influence of hydraulic oil additive on the fine reciprocating friction characteristics of steel and copper alloy. Hydraulic oils were prepared by blending a paraffinic mineral oil with zinc dithiophosphate (ZnDTP) and polyhydric alcohol ester as additives. The results show that the dynamic frictional characteristics vary mainly depending on the additive concentration. A specific additive formulation induces a unique amplitude-dependent friction behavior. In addition, the influence of different additives on the lubrication mechanism is investigated based on the instrumental analysis of the friction surface.

Effect of hydraulic oil additive on friction behavior of shock absorber sliding part

2020 ◽  
Vol 2020 (0) ◽  
pp. S11527
Author(s):  
Shinya NISHIZAWA ◽  
Yuki KUROIWA ◽  
Shinji KATO ◽  
Seiya WATANABE ◽  
Shinya SASAKI
Keyword(s):  
Shock Absorber ◽  
Friction Behavior ◽  
Hydraulic Oil

scholarly journals Dynamic Friction Parameter Identification Method with LuGre Model for Direct-Drive Rotary Torque Motor

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xingjian Wang ◽  
Siru Lin ◽  
Shaoping Wang
Keyword(s):  
Parameter Identification ◽  
High Performance ◽  
Controller Design ◽  
Identification Accuracy ◽  
Dynamic Friction ◽  
Direct Drive ◽  
Lugre Model ◽  
Friction Behavior ◽  
Identification Method ◽  
Friction Parameter

Attainment of high-performance motion/velocity control objectives for the Direct-Drive Rotary (DDR) torque motor should fully consider practical nonlinearities in controller design, such as dynamic friction. The LuGre model has been widely utilized to describe nonlinear friction behavior; however, parameter identification for the LuGre model remains a challenge. A new dynamic friction parameter identification method for LuGre model is proposed in this study. Static parameters are identified through a series of constant velocity experiments, while dynamic parameters are obtained through a presliding process. Novel evolutionary algorithm (NEA) is utilized to increase identification accuracy. Experimental results gathered from the identification experiments conducted in the study for a practical DDR torque motor control system validate the effectiveness of the proposed method.

Dynamic Friction Characteristics of Bulk Seeds Against Flat Vertical Surfaces

1992 ◽  
Vol 35 (2) ◽  
pp. 665-669 ◽  
Author(s):  
D. A. Irvine ◽  
D. S. Jayas ◽  
M. G. Britton ◽  
N. D. G. White
Keyword(s):  
Dynamic Friction ◽  
Friction Characteristics

The dynamic friction characteristics of a rapidly sheared granular material applied to the motion of snow avalanches

1993 ◽  
Vol 18 ◽  
pp. 215-220 ◽  
Author(s):  
J.D. Dent
Keyword(s):  
Shear Layer ◽  
Slip Plane ◽  
Flat Surface ◽  
Dynamic Friction ◽  
Friction Characteristics ◽  
Dynamic Friction Coefficient ◽  
Dispersed Particles ◽  
Number Of Layers ◽  
Shear Speed ◽  
Shearing Motion

A numerical simulation of simple two-dimensional shear of round uniform grains is used to investigate the dynamic friction characteristics of the layer of snow at the base of an avalanche. For steady, uniform flow on a uniform flat surface, the dynamic friction coefficient transmitted through the shear array is found as it varies with the shear speed and normal force applied to the top of the shear layer, and the properties of the particles in the shear layer.For this simple model, the flow in the shear layer is found to be independent of the total number of layers in the shear flow. A slip plane is formed along which most of the shearing motion takes places, so that the shear is confined to just two layers of particles which slide over one another. In the absence of gravity this slip plane jumps up and down randomly within the shear layer, which is otherwise composed of agitated semi-dispersed particles.

scholarly journals Cupronickel B10 and YG6 interface friction characteristics tested on a friction device for metal cutting

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401989022
Author(s):  
Chunjian Liu ◽  
Daochun Xu ◽  
Qingqing Li
Keyword(s):  
Friction Coefficient ◽  
Metal Cutting ◽  
Vibration Reduction ◽  
Interface Temperature ◽  
Friction Behavior ◽  
Conduction Model ◽  
Friction Characteristics ◽  
Interface Friction ◽  
Cupronickel B10 ◽  
Solid Liquid

Friction behavior is an important component of the metal-cutting mechanism. A simple and effective friction device that can yield the desired friction characteristics is required. In this article, a friction device with a solid–liquid–gas vibration reduction was proposed to research the interface friction characteristics. The interface friction characteristics of cupronickel B10 and YG6 were obtained through the new friction device, including the friction force, friction temperatures, and friction coefficient. The results show that an experimental solid–liquid–gas vibration reduction is feasible and effective to obtain the interface friction characteristics. The relationship between the friction-interface temperature T2 and the measured-point temperature T1 that was obtained by a heat-conduction model is linear. For cupronickel B10 and YG6, the friction coefficient gradually decreases with an increase in friction speed, and increases initially and then decreases with an increasing load. Based on the effect of friction temperature, friction speed, and load, a friction model for the interface friction characteristics of cupronickel B10 and YG6 was obtained.

Model-Based Investigation of Friction During Start-Up of Hydrodynamic Journal Bearings

1995 ◽  
Vol 117 (4) ◽  
pp. 667-673 ◽  
Author(s):  
A. Harnoy
Keyword(s):  
Friction Model ◽  
Journal Bearings ◽  
Time Variable ◽  
Stribeck Curve ◽  
Dynamic Friction ◽  
Stick Slip ◽  
Friction Characteristics ◽  
Start Up ◽  
Variable Friction ◽  
Steady Velocity

An analysis is developed for the time-variable friction during the start-up of a rotor system. The analysis is based on a dynamic friction model that has been developed from the theory of unsteady lubrication and can describe the observed friction characteristics. The model reduces to the Stribeck curve of friction versus steady velocity, and shows hysteresis curves in oscillating velocity. The “Dahl effect” of a presliding displacement before the breakaway is also included. The results indicate that the friction characteristics and energy friction losses, during the start-up, depend on a set of dimensionless parameters that represent the bearing as well as the dynamic system. The study shows that appropriate design and operation can prevent stick-slip friction and minimize wear during start-up.

Adhesive Effects on Dynamic Friction for Unlubricated Rough Planar Surfaces

2004 ◽  
Author(s):  
Xi Shi ◽  
Andreas A. Polycarpou
Keyword(s):  
Friction Coefficient ◽  
Mean Value ◽  
Friction Model ◽  
Major Influence ◽  
Dynamic Friction ◽  
Friction Behavior ◽  
Friction Forces ◽  
Normal Contact ◽  
Continuous Contact ◽  
Dynamic Friction Coefficient

As the size of contacting and sliding tribosystems decrease, intermolecular or adhesive forces become significant partly due to nanometer size surface roughness. The presence of adhesion has a major influence on the interfacial contact and friction forces as well as the microtribosystem dynamics and thus influences the overall dynamic friction behavior. In this paper, a dynamic friction model that explicitly includes adhesion, interfacial damping and the system dynamics for realistic rough surfaces was developed. The results show that the amplitude and mean value of the time varying normal contact and friction forces increase in the presence of adhesion under continuous contact conditions. Also, due to the attractive nature of adhesion, its presence delays or eliminates the occurrence of loss of contact. Furthermore, in the presence of significant adhesion, dynamic friction behavior is significantly more complicated compared to the no adhesion case, and the dynamic friction coefficient predictions may be misleading. Thus, it is more appropriate to discuss dynamic friction force instead of dynamic friction coefficient under dynamic conditions.

Parameter Identification of LuGre Friction Model: Experimental Set-up Design and Measurement

2015 ◽  
Author(s):  
Yun-Hsiang Sun ◽  
Tao Chen ◽  
Cyrus Shafai
Keyword(s):  
High Performance ◽  
Controller Design ◽  
Measurement Procedure ◽  
Friction Model ◽  
Operating Conditions ◽  
Dynamic Friction ◽  
Friction Modeling ◽  
Friction Behavior ◽  
Wide Range ◽  
Set Up

This work proposes a simple but general experimental approach including the rig design and measurement procedure to carry out a wide range of experiments required for identifying parameters for LuGre dynamic friction model. The design choice is based on accuracy of the estimated friction and flexibility in terms of changing contact conditions. The experimental results allow a complete LuGre model, which facilitates, but not limited to, other advanced friction modeling and high performance controller design if needed. In addition, several well-known dynamic friction features (varying break-away force, friction lag and presliding) are successfully demonstrated by our rig, which indicates the adequacy of our approach for capturing highly sophisticated and dynamic friction behavior over a wide range of operating conditions. The proposed set-up and the produced experimental data are believed to greatly facilitate the development of advanced friction compensation and modeling in friction affected mechanisms.

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