Mechanical Behaviour of Groundnut (cv Kampala) Kernel under Compressive Loading as a Function of Loading Rate and Orientation

Abstract

Mechanical properties of groundnut are vital tools in the design and development of its threshing, handling and processing equipment. This present research was carried out to evaluate the fracture resistance (rupture force, rupture energy and deformation at rupture) of Kampala groundnut kernels as influenced by loading rate and orientation.  The compression tests were carried out at three loading rates (15, 20 and 25 mm/min), under two orientations (axial and longitudinal).  The results showed that the loading rate and orientation had significant (p<0.05) effect on all the three mechanical parameters investigated. Based on the results obtained from this present research, the force, energy and deformation at rupture point of the groundnut kernel declined as loading rate increase from 15 to 25 mm/min, in both orientations. The average rupture force decreased from 86.07 to 62.80 N, at axial orientation; and 42.40 to 19.53 N, at longitudinal orientation. While the rupture energy decreased from 0.065 to 0.031 Nm, at axial orientation; and 0.031 to 0.02 Nm at longitudinal orientation. The high correlation values (r ≥± 0.90) showed a strong regression relationship between the mechanical parameters studied, loading rate and kernel orientation. Data obtained from this study will help in the design and development of groundnut kernel (mostly Kampala) handling and processing equipment.