Department of Mechanical Engineering

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https://ir.oauife.edu.ng/handle/123456789/328
Department of Mechanical Engineering

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Browsing Department of Mechanical Engineering by Author "Koya, O.A"

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    DEFORMATION AND DEHULLING OF SPONGE GOURD (LUFFA AEGYPTIACA) SEEDS
    (Taylor & Francis Group., 2011-03-03) Koya, O.A; Ogunsina, B.S; Opeyemi, O.O
    This work presents the compressive strength properties of sponge gourd (Luffa aegyptica) seeds to facilitate the design or adaptation of an appropriate dehuller. The sizes and shape indices of the seed and kernel, and the clearance of the kernel from the seed coat were determined. The seed samples were subjected to uni-axial quasi-static compression tests at 1.0 mm min−1 along the minor and the major axes. The fracture resistance, stiffness modulus, modulus of elasticity, toughness, and maximum elastic deformation of the seed were obtained from the force-deformation curve. The geometric mean diameters varied from 4.0 to 4.5 mm for the seed and 1.6 to 3.9 mm for the embedded kernel; while their corresponding sphericities were 0.64 and 0.62, respectively. The compressive strength of the seed varied with loading orientation. The seed exhibited larger deformation but lower stiffness along the major axis than the minor axis. The force required for rupturing the hull were 95 N along the major axis and 81 N along the minor axis; while the corresponding energy required were 95 and 40 mJ.
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    Deformation and fracture of dika nut (Irvingia gabonensis) under uni-axial compressive loading
    (Institute of Agrophysics, Polish Academy of Sciences, 2008-01-16) Ogunsina, B.S; Koya, O.A; Adeosun, O.O
    Fracture behaviour of dika nut under quasi-static loading along the longitudinal axis and the transverse axis was investigated. The fracture resistance of the nut was measured in terms of average force, deformation and toughness at nutshell fracture, and nut stiffness. Physical dimensions and shape of the nut, to provide for complementary input in design of handling equipment, were also determined. The force required to crack the nut increased with nut diameter but was not significantly different in both loading orientations. The mean cracking force was in the range of 2.06 to 3.67 kN. The compression of the nut exhibited a pronounced linearity between load and deflection. Dika nuts loaded along the transverse axis required less energy for nutshell fracture than those loaded along the longitudinal axis. Minimum toughness occurred with the small size nuts loaded along the transverse axis, thus providing base-line data in future design of an appropriate nutcracker.