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Effect of Loading Rate and Moisture Content on the Fracture Resistance of Beechwood ( Gmelina arborea ) Seed
NYORERE, O & UGURU, H
Abstract
Mechanical properties of agricultural materials are necessary for the proper design and development of
their planting, harvesting, handling and processing machineries. In this research, fracture resistance of whole gmelina seed
was evaluated in terms of its rupture force, rupture energy and deformation at rupture under four moisture content levels
and three loading rates. The quasi-static compressive tests were conducted at 20, 25, 30 and 35 percent moisture levels
(wb); and 5, 10 and 15 mm/min loading rates. Based on the results obtained, moisture content and loading rate had
significant (P ≤0.05) effect on all the three parameters investigated. The force required for initiating seed rupture decreased
with increase in moisture content and loading rate. The highest rupture energy was 0.268 Nm at 35% moisture content
under 5mm/min loading rate, and the lowest was 0.116 Nm at 20% moisture content under 15 mm/min loading rate. In
addition, the deformation capability of the seed decreased from 1.017 mm at 35% moisture content (wb), under 5 mm/min
loading rate, to 0.458 mm at 20% moisture content (wb) under 15 mm/min loading rate. The results obtained from this
research would be useful in the design and development of machines used in gmelina seed processing operations.
Keywords
Gmelina seed; Fracture resistance; Moisture content; loading rate
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