Engineering Commons^™

Investigation Of Surface Topology Effects On Metal Flow Of Aluminum And Steel During Hot Compression, Andrew Richard Matcha

Master's Theses (2009 -)

An investigation was conducted to study the effect of die surface roughness and lay on metal flow and the friction factor under lubricated hot compression. 6061-T6 aluminum and AISI 1018 steel rings and rectangular bar stock workpieces were compressed on H-13 tool steel platens of varying roughnesses ranging from Ra 0.25 – 6.1 µm (10 – 240 µin). Each platen was machined in such a way to ensure that the surface roughness would be unidirectional. Platen temperatures of 149 °C and 204 °C (300 °F and 400 °F) were used for all aluminum ring samples whereas platen temperatures ranging from …

Influence Of Frictional Or Rotational Kinetic Energy On Wellbore-Fluid/Temperature Profiles During Drilling Operations, Ahmed Q. Al Saedi, Ralph E. Flori, C. Shah Kabir

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Temperature-profile distributions in a wellbore during drilling operations might take different forms when applying the energy balance in the overall system. For steady-state conditions, wherein the wellbore is considered a closed system, adding any source of additional energy to this system can influence the predicted temperature profiles. This study presents a new analytical model to investigate the influence of rotational energy arising from the drillstring operation on the wellbore-temperature behavior.

A significant part of the drilling operation is rotation of the drillstring. Depending on the drilling rig, various equipment provides this kind of energy, such as the rotary table or …

Manufacturing And Testing The Permanent Magnet Linear Motor, Renjie Kang

Senior Theses

Controlled mechanical motion is vital in many useful applications in technology. Among them, linear motors have advantages over traditional rotating motors. In this work, we built a permanent magnet linear motor to test and measure its energy efficiency. A maximum 29% total energy efficiency, and 67% energy transfer rate, were detected. In addition, a C-shape support structure was added to the moving part in order to increase the moving accuracy. The tests show that, with the support structure, the fluctuation in the vertical direction decreases significantly, but the friction of the system slightly increases.

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 …

Development Of Electromagnetic Friction Dampers For Improving Seismic Performance Of Civil Structures, Mohsen Amjadian

Dissertations and Theses

Energy dissipation is critical to limiting damage to civil structures subjected to extreme natural events such as earthquakes. Friction is one of the most reliable mechanisms of energy dissipation that has been utilized extensively in friction dampers to improve seismic performance of civil structures. Friction dampers are well-known for having a highly nonlinear hysteretic behavior caused by stick-slip motion at low velocities, a phenomenon that is inherent in friction and increases the acceleration response of the structure under control unfavorably, in spite of the fact that the displacement is generally reduced because of the energy dissipation. This increase in acceleration …