Browsing by Author "Pearce, Howard"

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    A curriculum framework for flexible engineering degrees in South Africa
    (Quality Assurance Agency for Higher Education (Scotland), 2014-09-23) Grayson, Diane; Collier-Reed, Brandon I; Pearce, Howard; Shay, Suellen
    South Africa produces too few engineers to meet its development needs. The number of graduating engineers is slowly increasing, but is still only about 2000 per year, serving a population of over 50 million. Data from the Council on Higher Education (CHE 2013) show that for the 2005 cohort of BEng students nationally only 25% obtained an engineering degree in the regulation time of four years, with another 19% taking five years. In a study for the Engineering Council of South Africa on improving throughput (Fisher 2011), one suggestion was to increase curriculum flexibility to better cater for the needs of a diverse student population. As part of a CHE project, we developed exemplar curricula for engineering degrees designed to take either four or five years to complete. In this paper we describe the underpinning principles that guided the design and illustrate how they are applied in curriculum exemplars for a mechanical engineering degree.
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    The finite element of modelling of the dynamic behaviour of a transmission line conductor
    (1996) Kruse, Gunther Carl; Pearce, Howard
    The problem of conductor motion has been of concern to transrruss1on line engineers for many years. This thesis describes the application of one of the most powerful and useful tools of modern engineering, the finite element method, to the problem of modelling the dynamic behaviour of conductors. In modelling the conductor, the assumption that it may be treated as a solid continuum is made. Due to the construction of a conductor, however, the bending stiffness and internal damping of the conductor are non-linearly related to a number of factors. The results of a study on these factors are discussed in this thesis, and have been used where necessary in defining the material behaviour of a conductor. Four types of conductor motion are modelled, namely aeolian vibration, wake-induced vibration, bundle pinch (resulting from short-circuit currents) and the motion of a section of a transmission line after a conductor breaks. Finite element models have been developed specifically for each of these types of conductor motion, and the details of these are presented. The effects of various options in the finite element modelling, on the results obtained from the simulations, are also discussed. The finite element models are implemented by means of the finite element package, ABAQUS. Algorithms which have been developed and implemented by means of user-defined subroutines for the simulation of vortex shedding loads (in the case of aeolian vibration), electromagnetic forces (due to short circuit currents) and the loads experienced by a conductor in the wake of another, are discussed in the thesis.
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    Slamming analysis of skips in mine shafts: the effect of secondary stiffening in the guides
    (1991) D'Arcy, Evans A; Pearce, Howard
    Previous investigations into the dynamics of skips in deep mine shafts have led to the identification of slamming as a phenomenon that results in exceptionally high forces in the shaft steelwork and conveyance. Slamming may occur when the rollers on the skip, that normally act on the guide, fail. Possible damage caused to the shaft steelwork, as a result of slamming, limits the hoisting speed of the skip. This study extends previous work by investigating the effect of secondary stiffening, due to axial tension effects as the guide deforms, on the slamming response of the skip. A mathematical model of a single slamming event is formulated and a numerical solution procedure presented. A number of computer simulations, including parametric studies, are presented. An important conclusion is that previous slamming models were shown to predict a reduced response when low axial compressive forces are present in the guides while predicting an increased response for high (near the buckling load) axial compressive forces. The inclusion of secondary stiffening; due to axial tension effects, thus represents a significant refinement of the slamming model.