Abstract:

The compressive and static creep tests were conducted for the aeroponic potato tuber to analyze the effects of loading direction and loading rate on its rupture stress and strain. The creep process of the potato tuber was simulated using 4-element Burgers model to investigate its rheologic behavior. The compressive tests show that the yield limits and the rupture limits under different axial compressions of the aeroponic cultured potato tuber are lower than those of the soil cultured patato tuber with similar size. The effect of loading rate on the rupture stress of the aeroponic potato tuber structure is slight, but on the rupture strain is significant. The creep test results show that the aeroponic potato tuber appeass the obvious visco-elastic deformation and the viscous flowability. The fitted values of the element parameters in Burgers model can reflect accurately the rheologic properties of the aeroponic potato tuber, the filling precisions of the model under different axes are higher than 0.95. The obtained results provide a theoretical basis for reducing the mechanical damage of the aeropomic potato tuber in various production links.

Key words: agricultural engineering, seed potato, aeroponic culture, mechanical property, creep, Burgers mode