Research Articles

Permanent URI for this collection

https://wiredspace.wits.ac.za/handle/10539/21344
For information on accessing School of mechanical, industrial and aeronautical engineering Research Articles content please contact Salome Potgieter by email : salome.potgieter@wits.ac.za or Tel : 011 717 1961

Browse

Recent Submissions

Now showing 1 - 5 of 10
  • Thumbnail Image
    Item
    Project Management Assessments (PMAs): an empirical study
    (Southern African Institute for Industrial Engineering, 2018) Siriram, Rajenlall
    The objectives of this research are to: a) compare project management assessments (PMAs) from four firms across four industry sectors (75 PMAs are evaluated using known statistical techniques); b) validate the results through an expert panel; c) apply Pearson’s correlation analysis to find links in the PMA constructs and see how these links relate to the overall project result; and d) identify areas for further research. Three hypotheses are tested, and reveal differences and similarities in project management practices. The results provide interesting opportunities for researchers and for project management practitioners. Finally, a discussion, the limitations of the study, and suggestions for further research are presented.
  • Thumbnail Image
    Item
    The response of layered anisotropic tubes to centrifugal loading.
    (Elsevier, 2016-04) Carpenter, H.W.; Reid, R.G.
    The displacement-based elastic solution for layered anisotropic tubes is extended to allow for the presence of centrifugal loading. The additional terms in the stress-strain equations derived in this work are validated by comparing the results obtained using the current solution against those determined using finite element simulation of rotating thin and thick-walled glass fibre reinforced plastic tubes of arbitrary anisotropic lay-up. The solution is presented in such a form that it can be utilised to determine the linear thermo-mechanical behaviour of rotating tubes with anisotropic lay-up, subjected to any combination of internal and external axisymmetric pressure, axial loading, torsional loading, and constant temperature change.
  • Thumbnail Image
    Item
    Effects of processing conditions on the mechanical and water absorption properties of resin transfer moulded kenaf fibre reinforced polyester composite laminates.
    (Elsevier, 2010-11) Rassmann, S.; Reid, R.G.; Paskaramoorthy, S.
    This paper focuses on the mechanical and water absorption properties of kenaf fibre reinforced polyester laminates manufactured by resin transfer moulding. Varying processing conditions were considered as alternatives to fibre treatments, thereby potentially avoiding additional cost and complexity in the manufacturing process. Laminates were produced by altering fibre moisture content, mould temperature and mould pressure following injection. Tensile, flexural, impact and water absorption tests were conducted. Processing conditions were found to have little effect on properties except for pressurisation which increased tensile and flexural strength and decreased water absorption at low fibre volume fractions. Examinations using a scanning electron microscope showed that all the laminates failed by fibre pull-out.
  • Thumbnail Image
    Item
    A novel method to measure residual stresses in unidirectional GFRP.
    (Elsevier, 2009-05) Reid, R.G.; Paskaramoorthy, R.
    A few methods are available for measuring the residual stresses that occur in the simplest of all possible composites structures - the unconstrained unidirectional laminate. None of them, however, are suitable for use on GFRP. A new method is presented whereby the stresses in a unidirectional GFRP laminate can be determined. The method relies on releasing the constraints between fibre and resin through an annealing process. The strain in the glass fibres is thus obtained, which allows the elastic stresses within the fibres and the resin to be determined. In this way, it is not necessary to take account of plasticity and viscous effects in the polymer in order to determine the stresses within the laminate. Results for unidirectional laminates initially manufactured to contain differing residual stresses are presented and discussed.
  • Thumbnail Image
    Item
    An extension to classical lamination theory for use with functionally graded plates.
    (Elsevier, 2011-01) Reid, R.G.; Paskaramoorthy, R.
    An extension to classical lamination theory is presented for the improved analysis of thin to moderately thick functionally graded plates. The method results in an explicit formulation that accommodates any through-thickness variation in the elastic, hygrothermal and piezoelectric properties of each layer. Additionally, variations in the material rotation angle, temperature, moisture content and electric field strength through each layer are taken into account. The method relies on representing with polynomial series the variation in both the properties of each ply and the hygrothermal and piezoelectric loading. Validation problems are presented that demonstrate the application and accuracy of the method.