Finite Element Analysis and Feasibility of Simple Stochastic Modeling in the Analysis of Fissuring in Grains during Soaking

Authors: Jonathan H. Perez, Fumihiko Tanaka, Daisuke Hamanaka, Toshitaka Uchino

Abstract:

A finite element analysis was conducted to determine the effect of moisture diffusion and hygroscopic swelling in rice. A parallel simple stochastic modeling was performed to predict the number of grains cracked as a result of moisture absorption and hygroscopic swelling. Rice grains were soaked in thermally (25 oC) controlled water and then tested for compressive stress. The destructive compressive stress tests revealed through compressive stress calculation that the peak force required to cause cracking in grains soaked in water reduced with time as soaking duration was extended. Results of the experiment showed that several grains had their value of the predicted compressive stress below the von Mises stress and were interpreted as grains which become cracked and/or broke during soaking. The technique developed in this experiment will facilitate the approximation of the number of grains which will crack during soaking.

Keywords: Cracking, Finite element analysis, hygroscopic swelling, moisture diffusion, von Mises stress.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1086679

References:

[1] T. Genkawa, T. Uchino, A. Inoue, F. Tanaka and D. Hamanaka, “Development of a low-moisture-content storage system for brown rice: Storability at decreased moisture contents,” Biosystems Engineering, vol. 99, no. 4, pp. 515-52, Dec. 2008.
[2] T. Genkawa, T. Uchino, A. Inoue, F. Tanaka and D. Hamanaka. “Incidence of open crack formation in short-grain polished rice during soaking in water at different temperatures” Journal of Food Engineering, vol. 103, no. 4, pp. 457-46, Apr. 2011.
[3] S. Koide, T. Takko and Y. Nishiyama, “Open crack formation in rice with cracked endosperm and cracked surface during soaking.” (in Japanese with English abstract). Journal of the Japanese Society of Food Science and Technology, vol. 4, no.1, pp. 69-72, 2001.
[4] S. Murata, S. Koide and T. Kawano, “Study on the cracking of polished rice soaked in water.” (in Japanese with English abstract), Journal of the Japanese Society of Agricultural Machinery, vol. 54, no. 1, pp. 67-72, 1992.
[5] J. H. Perez, F. Tanaka, T. Uchino, “Comparative 3D simulation on water absorption and hygroscopic swelling in japonica rice grains under various isothermal soaking conditions.” Food Research International, vol. 44, no. 9, pp. 2615-2623, Nov. 2011.