Masters Degrees (Industrial Engineering)

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Browsing Masters Degrees (Industrial Engineering) by browse.metadata.advisor "Akdogan, G."

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    Development of a continuous improvement framework for a small scale steelmaking company
    (Stellenbosch : Stellenbosch University, 2018-03) Dondofema, Richmore Aron; Matope, Stephen; Akdogan, G.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: The South African steelmaking industry is currently sailing through a turbulent economic period characterised with commodity price instability and competition from European and Asian markets. This research study focuses on creating a production cost advantage for a local steelmaking organisation through the implementation of a continuous improvement (CI) framework. Implementing CI activities focuses on product value creation by systematic identification and elimination of process waste in the production process on a continuous basis. Through a systematic literature review on the applications of lean manufacturing in South Africa, the research identified that there was limited application of continuous improvement techniques in steelmaking sector. The study further investigated the development of the South African steel industry and applications of Industrial Engineering (IE) principles to the industry. Findings of this review buttressed the absence of IE systematic research for steelmaking in South Africa. To understand continuous improvement, the student used conceptual framework analysis (CFA), a non-deterministic research tool that provides a method to conceptualise a specific subject. The identified concepts of continuous improvement are: CI process management, organisational infrastructure and supportive framework, and CI techniques. These three concepts were used to construct a CI implementation framework for Unica Iron and Steel Company in Hammanskraal, Pretoria. The implementation framework consists of a cycle with six CI process management steps which include process audit, identification of areas of improvement, improve, optimise, sustain and review. The framework is based on the following CI techniques: Lean Manufacturing, Toyota Production System, Six Sigma and Theory of Constraints. To successfully implement CI activities the organisation should have proper channels of communication between line employees, supervisors and operational managers as organisational infrastructure and supportive framework aspects. To assist in the validation of the CI implementation framework, Technomatix simulation software was used. From the results obtained through simulation, the first improvement cycle revealed 78% improvement in throughput per shift.
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    An investigation of fretting wear in aerospace applications
    (Stellenbosch : Stellenbosch University, 2011-12) Nortje, Hermann; Akdogan, G.; Oosthuizen, G. A.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: Fretting wear results in the loss of fit and tolerance at contact interfaces. The aerospace and aircraft industry is severely impacted by fretting wear and fretting fatigue that frequently occurs in turbo machinery and riveted structural connections. There have been numerous studies, investigating the fretting phenomenon for these aerospace applications. Literature available in regard to fretting wear encountered in these aerospace applications is limited. This study is therefore aimed at investigating the fretting wear encountered in aerospace application. An in-house fretting test apparatus was specially designed and developed in order to perform the fretting wear experiments. Ti-6Al-4V and Al7075-T6 are the two aerospace materials that were tested using the fretting test apparatus. An extensive experimental study was conducted in order to investigate the effect of the normal force on the fretting wear and friction behaviour of the two aerospace materials. The most severe of these experiments were identified and then repeated for up to 106 fretting cycles. Additional fretting wear experiments were also conducted between the two aerospace materials and cemented carbides, since the carbides are currently being utilized as coatings in some aerospace contacts that are prone to fretting induced damage. The experimental study revealed that a decrease in the normal force resulted in an increase in the severity of the fretting wear of both aerospace materials. The additional fretting wear experiments involving carbide-metal contact couples found that Ti-6Al-4V and Al7075-T6 were prone to adhesive wear.
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    An investigation of sliding wear of Ti6Al4V
    (Stellenbosch : Stellenbosch University, 2012-03) Herselman, Emile Johan; Akdogan, G.; Oosthuizen, G. A.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: Sliding wear is a complicated form of wear involving different factors. The factors affecting the process are the mechanical properties of the materials, sliding distance, sliding speed, and normal force applied to the contact. An experimental study was conducted to assess the performance of Ti6Al4V in self-mated and various counterface material contact couples subjected to linear reciprocating dry sliding motion. The normal force was varied for all the experiments to understand the effect it had on specific couples. Sliding wear experiments were also conducted on cemented carbides coupled with Ti6Al4V. In certain applications carbide coatings are used and could possibly come into contact with Ti6Al4V. Cemented carbides used in the study were manufactured through spark plasma sintering and liquid phase sintering. An in depth study was conducted to assess the spark plasma sintered materials and compare these to those manufactured through liquid phase sintering. The experimental study revealed that an increase in normal force, in sliding experiments, led to an increase in friction and wear volume loss of the Ti6Al4V pin. In addition the experiments found that Ti6Al4V was prone to adhesion and surface oxidation.