Engineering Commons^™

Effect Of Water-Based Nanolubricant Containing Nano-Tio2 On Friction And Wear Behaviour Of Chrome Steel At Ambient And Elevated Temperatures, Hui Wu, Fanghui Jia, Jingwei Zhao, Shuiquan Huang, Lianzhou Wang, Sihai Jiao, Han Huang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part B

A novel experimental method was developed through a ball-on-disk tribometer to study the friction and wear behaviour of a chrome steel at temperatures of 25, 200 and 500 °C. Water-based nanolubricants containing different concentrations of nano-TiO2 from 0.4 to 8.0 wt% were used to investigate their effects on friction-reduction and anti-wear mechanisms, in comparison to the benchmarks under dry and water conditions. The results show that the water-based nanolubricants can significantly reduce coefficient of friction (COF) and improve wear resistance of the chrome steel at both ambient and elevated temperatures. In particular, the use of nanolubricant containing an optimal concentration …

Oxide Scale Characterization Of Ferritic Stainless Steel And Its Deformation And Friction In Hot Rolling, Xiawei Cheng, Zhengyi Jiang, Dongbin Wei, Liang Hao, Jingwei Zhao, Laizhu Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

The oxidation kinetics of ferritic stainless steel 430 was studied in dry and humid air at 1090 °C by Thermo Gravimetric Analysis (TGA). Different atmospheres and heating times were adopted for reheating to obtain different compositions and thickness of the oxide scale. Hot rolling was performed on a 2-high Hille 100 experimental rolling mill at various reductions. Oxide scale thickness and composition were analysed with optical microscopy (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). The surface profiles were examined by a digital microscope, and the topographic features of the thin oxide scale surface were examined with an atomic …

Comparative Study Of Vehicle Tyre-Road Friction Coefficient Estimation With A Novel Cost-Effective Method, Boyuan Li, Haiping Du, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

This paper qualitatively and quantitatively reviews and compares three typical tyre-road friction coefficient estimation methods, which are the slip slope method, individual tyre force estimation method and extended Kalman filter method, and then presents a new cost-effective tyre-road friction coefficient estimation method. Based on the qualitative analysis and the numerical comparisons, it is found that all of the three typical methods can successfully estimate the tyre force and friction coefficient in most of the test conditions, but the estimation performance is compromised for some of the methods during different simulation scenarios. In addition, all of these three methods need global …

A Novel Cost Effective Method For Vehicle Tire-Road Friction Coefficient Estimation, Boyuan Li, Haiping Du, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

The tire-road friction coefficient is critical to vehicle longitudinal, lateral and roll dynamics and control because tire is the only contact part between the vehicle body and the road. However, direct measurement of tire-road friction coefficient is impossible in practice. This paper presents a novel cost effective method for vehicle tire-road friction coefficient estimation. This method only needs the measurements of the wheel angular velocity, the traction/brake torque and the longitudinal acceleration, which are all available from the commonly installed sensors in ordinary passenger vehicles, and can be used to estimate the individual tire-road friction coefficient. There are three steps …

Effect Of Particle Properties On The Discrete Element Simulation Of Wall Friction, Andrew Grima, Peter Wypych

Faculty of Engineering and Information Sciences - Papers: Part A

Modelling the interaction between particles and boundaries is of great interest and importance in many Discrete Element Method (DEM) applications where boundary failure conditions dictate the flow behaviour and velocity gradients of a bulk material. Bulk wall friction angles in DEM models are dependent on the mechanical properties of the particles and boundary material as well as the constraints of the contact models used, especially the tangential and rolling torque components. This paper examines the parameters determined from the calibration inclination test by conducting direct wall shear tests to validate the accuracy of the calibration parameters and the sensitivity of …

Some Influences On Wall Friction Measurements - A Preliminary Investigation, Wendy Halford, Cameron Lawler, Andrew P. Grima, Peter C. Arnold

Faculty of Engineering and Information Sciences - Papers: Part A

The concept of measuring the friction between a bulk solid and a wall material is very simple. However, experience together with previous wall friction measurement research suggest that variables that influence wall friction values are difficult to quantify and, so far, are proving unreliable to predict with any degree of confidence. In this paper some preliminary test results are presented for different bulk solids on different wall plates where variables examined include particle size distribution, moisture content, test cell size and shear speed. The outcomes presented confirm the authors' belief that with the present state of knowledge about wall friction …

Study On Surface Roughness And Friction During Hot Rolling Of Stainless Steel 301, Dongbin Wei, Zhengyi Jiang, Junxia Huang, Aiwen Zhang, Xu Shi, Sihai Jiao

Faculty of Engineering and Information Sciences - Papers: Part A

A well-defined boundary condition is important for generating an accurate model for simulating metal forming process. It is important to characterize the features of the oxide scale in hot rolling of stainless steel strip. Short time oxidation tests in humid air with water vapor content of 7.0 vol. % were carried out using Gleeble 3500 thermo-mechanical simulator. The deformation, surface morphology of oxide scale, and the friction in hot rolling were studied by conducting hot rolling tests. The results show that the surface roughness decreases with an increase of reduction. The effect of oxide scale on friction and surface roughness …

Investigation Of Measuring Wall Friction On A Large Scale Wall Friction Tester And The Jenike Direct Shear Tester, Andrew Grima, Brendan P. Mills, Peter W. Wypych

Faculty of Engineering - Papers (Archive)

The interaction of a granular material with boundary materials is one of the most important factors to consider when designing mass flow hoppers, chutes, feeders and other equipment where flow is expected to occur. Numerous properties of a bulk material and wall surface influence the measurement of wall friction angles (e.g. particle size and distribution, particle shape, particle and boundary asperities and moisture content) which can be difficult to thoroughly investigate on a standard Jenike direct shear tester. Often the Jenike direct shear tester is limited to small particle sizes, wall sample materials, shear rates and displacements.This paper presents the …

The Effect Of Friction On Magnetorheological Fluids, W H. Li, X Z. Zhang

Faculty of Engineering - Papers (Archive)

This paper presents an experimental approach to study the effect of friction on magnerorheological (MR) fluids. Both steady and dynamic modes were employed to investigate MR fluid behaviors. The experimental results indicate that the total MR effects are dominated by two factors: magnetic force and friction force. Conventionally, the magnetic force contribution to MR effect has been intensively studied while the friction force effect has attracted less attention. This study provides a method to quantitatively predict the friction contribution to the total MR effect. It may be used to effectively analyze enhanced MR effects reported by other groups. Also, it …

Modelling Solids Friction Factor For Dense-Phase Pneumatic Conveying Of Powders, Peter W. Wypych, David B. Hastie

Faculty of Engineering - Papers (Archive)

This paper presents results from an investigation into power-function modelling of solids friction factor for the dilute-phase and fluidised dense-phase (FDP) conveying of powders. Three different diameters/lengths of pipeline were used to generate a wide range of steady-state data and also explore important scale-up issues. The effect of pressure tapping locations on the data and derived models was also investigated. Different sets of power-function model solutions were used for comparison purposes and also to check scale-up stability and accuracy. Comparisons with predictions from recent models developed by other researchers are included. It is concluded that certain forms of the power …

Friction In The Roll Bite Under Various Hot Rolling Conditions, Weihua Sun, A. K. Tieu, Hongchun Li, Zhengyi Jiang, Guodong Wang, Xianghua Liu

Faculty of Engineering - Papers (Archive)

In this paper, the effect of hot rolling parameters on the friction coefficient was studied by inverse calculation on the experimental roll loads where the hot rolling experiments were carried out at

7.5-45.0% reductions, 0.12-0.72m/s speeds and temperature of 850-1025°C. Dry rolling, water, oil/water mixture emulsion and pure oil were used as lubricants in the experiments. In carrying out the calculation, a flow stress model for the present test material was first obtained experimentally. Hot rolling parameters, including reduction, roll speed, work piece entry temperature and lubrication conditions, were investigated to determine their effect on friction coefficient and mill loads. …

Friction And Asperity Contact In Strip Rolling, A. K. Tieu, Zhengyi Jiang, Cheng Lu, Prabuono B. Kosasih

Faculty of Engineering - Papers (Archive)

This paper reviews different aspects of friction and asperity contacts in strip rolling. The mixed film lubrication model considers the effect of asperity flattening and the lubrication within the working zone. The oil concentration of the emulsion at entry and throughout the roll bite is considered together with the thermal effects of the contacts. The actual area of contact due to asperity deformation can be determined from a 3-wavelength FEM model. The deformation of a randomly generated surface of the hot strip with oxide scale can also be modeled by an FEM method. The friction variation in the roll bite …

3d Finite Element Analysis Of Surface Roughness And Friction In Hot Strip Rolling, Zhengyi Jiang, A. K. Tieu

Faculty of Engineering - Papers (Archive)

Surface roughness of oxide scale and strip in hot strip rolling has a significant influence on the friction and lubrication conditions. In this paper, the authors present the measured surface roughness of oxide scale and strip by Atomic Force Microscope (AFM) and Surface Profilometer respectively for hot rolled strip on a Hille 100 experimental rolling mill. Based on the friction coefficient determined through a sensor roll on the rolling mill, a 3D rigid visco-plastic finite element simulation was carried out, and the relationship between the surface roughness and friction coefficient was investigated. Results show that the lubrication in hot strip …

Computer Control Of Machines With Friction For Precise Motion, Simon Webb, Zheng Li, Christopher David Cook

Faculty of Engineering - Papers (Archive)

We study the problem of precise control of machines with static and Coulomb friction. An experimental X-Y testbed built for testing various control methods is described and initial experimental results are presented. A simple pole placement controller is designed for computer control of the X-Y testbed based on a generalised sampled-data hold. Robustness and stability of the controller are analysed. Simulation suggests that this controller is able to achieve precise position control even when parameters of both the dynamics of the machine and the characteristics of friction are unknown