Determination of Poisson’s ratio and elastic modulus of African nutmeg (Monodora myristica)

An investigation into the Poisson’s ratio and elastic modulus of African nutmeg as a function of moisture content and loading rate was carried out. Quasi-static compressive tests were conducted at moisture levels of 8, 11.2, 14, 17.4 and 28.7% (d.b.) in an axial loading orientation. Both unit lateral extension and unit normal compression values were determined. Average values of 0.512 to 0.275 were obtained for moisture levels of 8 to 28.7%, respectively. Effects of loading rates were also investigated and results show that Poisson’s ratio increased from 0.136 to 0.334 at loading rates of 1 and 7 mm min-1, respectively. Elastic modulus was observed to decrease as moisture increased. Average values of 201.5 to 41.30 N mm-2 were noted for moisture levels of 8 to 28.7%, respectively. A similar negative trend was observed with loading rate. These finding could therefore be useful in predicting the load deformation behaviour of African nutmeg.