Aims: To review the broad spectrum of engineering materials used in sports applications in terms of their strength, stiffness, toughness and ductility. To characterise the elastic and viscoelastic properties of these materials. To examine the performance of materials in sports applications using case studies.
Learning Outcomes:
The students should be able to understand the role of different classes of materials in a range of applications within sports engineering. They should be aware of the advantages and limitations of these materials in terms of their fundamental mechanical properties and in terms of case histories.
Skills:
Facilitated - intellectual, practical, key.
Content:
The materials spectrum: Materials resources, classification in terms of cost, embodied energy and environmental profile, Ashby diagrams for stiffness, strength and toughness, stress versus strain characteristics. Theory of elasticity: The stress and strain matrices, elastic stiffnesses and compliances, fully expanded Hooke's Law, isotropic (e.g. steel, glass), orthotropic (e.g. fibres, wires), thin orthotropic plates (e.g. composites, plywood) materials. Theory of viscoelasticity: Time-dependent mechanical response of materials, including polymers, rubbers, fibres, foams and composites, as a function of temperature and frequency. Creep, stress relaxation, hysteresis, damping. Wood in sport: Structure and properties of wood, density, moisture-dependence, mechanical properties, hardness, impact resistance, natural durability and preservation, selection, countries of origin, environmental issues, sustainability. Case study on selection of wood species for cricket bats. Natural and synthetic polymers in sport: Brief introduction to the classification, structure, and properties of polymers. Case studies include selected topics from the following: an examination of cork and leather for cricket bats, foam in skis and polymers for running shoes. Fibres: Fibre structure, melt spinning, cold drawing, ultra-stiff fibres, glass, carbon and aramid fibres, steel wire, whiskers. Case studies include topics such as flexible fibre assemblies for wide span sports stadiums and climbing ropes. Textiles: Flexible fibre assemblies, weaving, design of 2-D and 3-D weaves, non-wovens, textile terminology, synthetic and natural fibres and fabrics, comfort factors in clothing. Ceramics: Piezoelectric fibres in tennis rackets and skis.
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