Muhammad Usman Abdullah

Muhammad Usman Abdullah
Bournemouth University | BU · School of Design, Engineering and Computing

MSc Mechanical Engineering

About

15
Publications
4,221
Reads
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35
Citations
Introduction
I am a mechanical engineer and a materials science enthusiast. My main research interests are Mechanics, Materials, and Computational Modelling. I use experimental methods along with advanced material characterisation techniques combined with finite element modelling to understand plastic deformation, microstructural alterations and residual stress formation. I study material response to dynamic loading conditions within the context of tribo-mechanics, thermo-mechanical and chemical interactions
Additional affiliations
May 2016 - September 2017
National University of Sciences and Technology
Position
  • Lecturer
November 2012 - May 2016
National University of Sciences and Technology
Position
  • Laboratory Engineer
Education
May 2014 - May 2016
National University of Sciences and Technology
Field of study
  • Mechanical Engineering
August 2008 - May 2012
University of Engineering and Technology, Taxila
Field of study
  • Mechanical Engineering

Publications

Publications (15)
Article
Subsurface microstructural alterations are formed in the later stages of rolling contact fatigue (RCF) under high contact pressure. The subsurface changes observed as a dark contrast under optical microscopy are classified as Dark Etching Regions (DERs). Despite the fact that DERs have been presented for several decades, the understanding of its de...
Article
Full-text available
Rolling bearing elements develop structural changes during rolling contact fatigue (RCF) along with the non-proportional stress histories, evolved residual stresses and extensive work hardening. Considerable work has been reported in the past few decades to model bearing material hardening response under RCF; however, they are mainly based on torsi...
Article
Bearing steel under severe loading condition undergoes substantial subsurface microstructural alterations known as Dark etching regions and white etching bands. White etching bands (WEBs) develop after hundreds of millions of stress cycles in bearing components and have been reported for several decades but the formation mechanism of white bands is...
Article
The performance and durability of tribological components in roller follower valve train is governed mainly by the roller rotational behaviour. Pure rolling of roller on the camshaft surface is essential to achieve the optimum valve train efficiency. The increase in roller slip can lead to high valve train power loss due to increase in sliding fric...
Article
Full-text available
The environmental concerns associated with artificially formulated engine oils have forced a shift towards bio-based lubricants. The deposition of hard coatings on engine components and migrating to environmentally friendly green lubricants can help in this regard. Chemically modified forms of vegetable oils, with better low-temperature characteris...
Conference Paper
The bearing material operated under RCF is subjected to the triaxial stress state where work hardening followed by softening has been reported under the contact track. Such nonconformities (hardening/softening along with microstructural alterations) create complexities to model the cyclic hardening of bearing material under RCF. Current study prese...
Article
In roller follower valve train, proper rolling of roller reduces the chances of fatigue failure and power losses. During engine operation, the roller does slip on the camshaft surface. The oil film thickness plays an important role on the roller sliding which necessitates experimental investigations. A modern gasoline engine valve train has been in...
Article
Purpose There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the pote...
Article
Purpose This paper aims to present a technique that has been developed to study the wear in the camshaft and tappet. The engine manufacturers use the most suitable materials, lubrication additives and surface coatings to minimize friction in all the components of the engine. Reduced friction results in less wear of critical engine components. The r...
Conference Paper
Full-text available
: Friction reduction is an effective way to achieve better fuel economy while maintaining reduced exhaust emissions in engines. The friction characteristics in engine valve train vary directly with the operating temperature, lubricant pressure, lubricant chemistry, camshaft speed and type of engine. Substantial experimental work has been carried ou...
Conference Paper
Full-text available
Engine valve train is normally subjected to severe operating conditions varying in nature of oil inlet pressure and operating temperature which can affect the tribological behavior of roller follower significantly and thus the overall performance of engine valve train. Little to no experimental work has been reported/carried out on the effects of l...
Conference Paper
Full-text available
Some products for automotive industries are difficult to manufacture using the conventional metal casting processes. In such situation different methods are combined to form a hybrid casting process. The hybrid casting process is a technique in which different casting process are combined to get a cast product. Therefore, the hybrid casting techniq...
Conference Paper
In an internal combustion engine, further improvements in the design and development phase is difficult therefore different companies intend to bring changes in other aspects like lubricant, lubricating system, cooling system, fuel and fuel system. The temperature of engine is monitored indirectly by temperature sensor, but this temperature is of c...
Conference Paper
A controlled wind tunnel test facility is essential for the study of aerodynamics, external flow characteristics as well as the calibration of wind measuring instruments. Reliability of the findings of such a facility depends on the regular assessment of flow quality and instrumentation of the wind tunnel against the relevant standards. Recently, t...

Questions

Question (1)
Question
How can we pre-define uneven stresses in a material during Abaqus modeling? The one method that I know, is to use previous *.Odb file to define stresses in current model. But I am looking for alternative to do that as my stress values came for experimental measurements. Any suggestion or link would be really helpful.

Projects

Project (1)
Project
Tribological performance evaluation of valvetrain in Toyota Prius 1NZ engine head with the application of Wonder Prcoess Craft surface treatment process. The aim and scope is to the reduce the roller sliding phenomenon of valvetrain system with the application of WPC surface treatment in a real production engine head under actual conditions.