A Method for Numerical Analysis of Stresses in Rice Kernel During Drying Process

Abstract

The estimation of stresses in a rice kernel will be necessary for discussing the stress cracking in the kernel. A few studies have been reported for the stress analysis in biological materials. Those studies, however, can not be applied to estimate the stresses in the rice kernel because of the insufficiencies on the description of the analysis. In this paper, a calculation method was presented for the stresses in a rice kernel which could be assumed to be a linear viscoelastic sphere under the influence of a radial moisture distribution.
As shown in the previous paper, the stress-strain relationships for the rice endosperm were those for a continuous Maxwell viscoelastic body with temperature and moisture dependent properties. It could be assumed that the rice endosperm was thermo- and hydro-rheologically simple. The present analysis would be based on the generalized relaxation integral law which was applicable to the thermo- and hydro-rheologically simple materials such as the rice endosperm, but the dilatational response of the rice kernel would be purely elastic. A finite difference method was applied to the calculation of the relaxation integral law.