Engineering Commons^™

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