The ability of waterborne coatings to adhere to polypropylene-based substrates is a challenge in the automotive industry. This thesis seeks to explore novel methods to improve the adhesion and provide coated substrates of an industrial standard. Two methods are explored, whereby a physical entanglement method is found to be unsuccessful but a chemical bonding method is found to give patentable results. It is found that the UV curing of carbene precursors as candidate adhesion promoters, gives an adhesive force which is comparable to the industrial state of the art method, flaming. Initially, the UV energy initiates CH insertion reactions, which covalently graft the adhesion promoter to the polypropylene surface. Secondly, the hydrophilic functional groups of the adhesion promoter adhere to the waterborne basecoat, thus optimal adhesion is achieved. Statistical modelling of the results reveals that the adhesive strength depends on the UV intensity, the adhesion promoter concentration and functional group type. To explore the industrial applicability, the safety and stability during storage and the aesthetics of the adhesion promoters were investigated. This research is the first step to developing a formulation that is able to replace the current flaming method.

Ti-5Al-5Mo-5V-3Cr (Ti-5553), a relatively new generation beta titanium alloy has the advantage of high strength. It is a current generation alloy used in landing gear. Currently, landing gear components are large scale and processed through forging, followed by complex heat treatments. HIPping (hot isostatic pressing) is an alternative way to process this alloy. In this project, work was carried out on investigating microstructures and mechanical properties of HIPped Ti-5553 alloy. During comparisons on fracture toughness of different types of specimens, specimens are first heat treated to a similar strength level. And fracture toughness values are calculated at the same strength level circumstance. Various microstructures are obtained through different heat treatments. Different microstructures can be achieved through specified treated temperature/ time and quenching methods. Results show that larger grain size and coarser intergranular lath-like grain boundary alpha can improve the fracture toughness. One shell-like microstructure is obtained through different heat treatment conditions. Mechanical test was carried out on this kind of microstructure and compared to normal beta annealed microstructures. To investigate the influence of microstructure on fracture toughness, techniques including optical microscope (OM), scanning electron microscope (SEM), and confocal laser scanning microscope have been used.

Thesis (MBA) --University of Limpopo, 2008 / Despite crucial strategic value of fleets, most organizations have relegated the management of their vehicles as being very low on their list of priorities. Consequently, they are entrusting unsuitable people with management of their fleet. Without proper management, huge amounts of money are wasted through fuel fraud and with repairs being done too late or not at all, leaving expensive vehicles idle for months (Barrow 1999).It has been observed that managing fleets with the emphasis on bookkeeping and finance, rather than operational realities, leads to huge and unnecessary costs and massive fraud (Barrow 1998). Efficiency in fleet management is about having a fleet that works directly to support the organizational goals. It is imperative that a study was conducted to analyze the situation of pool cars in the Department of Water Affairs and Forestry (DWAF) in the Limpopo Province to ensure the efficiency in its fleet management

Abstract not available

This thesis explores the elastic behaviour of the mechanical double action press and draw die system commonly used to draw sheet metal components in the automotive industry. High process variability in production and excessive time spent in die try-out are significant problems in automotive stamping. It has previously been suggested that the elastic behaviour of the system may contribute to these problems. However, the mechanical principles that cause the press system to affect the forming process have not been documented in detail. Due to a poor understanding of these problems in industry, the elasticity of the press and tools is currently not considered during the die design. The aim of this work was to explore the physical principles of press system elasticity and determine the extent to which it contributes to problems in try-out and production. On the basis of this analysis methods were developed for controlling or accounting for problems during the design process. The application of frictional restraining force to the edges of the blank during forming depends on the distribution and magnitude of the clamping force between the binders surfaces of the draw die. This is an important control parameter for the deep drawing process. It has been demonstrated in this work that the elasticity of the press and draw die can affect clamping force in two ways. The response of the press system, to the forces produced in the press during forming, causes the magnitude of clamping force to change during the stroke. This was demonstrated using measured data from a production press. A simple linear elastic model of the press system was developed to illustrate a definite link between the measured force variation and the elasticity of the press and tools. The simple model was extended into a finite element model of the complete press system, which was used to control a forming simulation. It was demonstrated that stiffness variation within the system could influence the final strains in a drawn part. At the conclusion of this investigation a method is proposed for assessing the sensitivity of a part to clamping force variation in the press during die design. A means of reducing variation in the press through the addition of a simple linear spring element is also discussed. The second part of the work assessed the influence of tool structure on the distribution of frictional restraining forces to the blank. A forming simulation showed that tool stiffness affects the distribution of clamping pressure between the binders. This was also shown to affect the final strains in a drawn part. However, the most significant influence on restraining force was the tendency of the blank to increase in thickness between the binders during forming. Using a finite element approximation of the try-out process it was shown that the structure of the tool would also contribute to the problems currently experienced in try-out where uneven contact pressure distributions are addressed by manually adjusting the tool surfaces. Finally a generalised approach to designing draw die structures was developed. Simple analysis methods were combined with finite element based topology optimisation techniques to develop a set of basic design guidelines. The aim of the guidelines was to produce a structure with uniform stiffness response to a pressure applied at the binder surface. The work concludes with a recommendation for introducing the methods developed in this thesis into the standard production process.

Thesis--Technische Universität Dresden, 2007. / Includes bibliographical references.

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). "August 2009." Includes bibliographical references (leaves 279-296). Also available via the World Wide Web.

Thesis (M.A.)--Naval Postgraduate School, Monterey, Calif., 2001. / "September 2001." Includes bibliographical references (p. 87-90). Available also online as a PDF file via the World Wide Web.

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Okenwa Okoli, Florida State University, FAMU-FSU College of Engineering, Dept. of Industrial & Manufacturing Engineering. Title and description from dissertation home page (viewed Mar. 3, 2004). Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 81-85).