Modeling and simulation of creep response of sorghum stems: Towards an understanding of stem geometrical and material variations

Sorghum [ bicolor (L.) ] is a tropical grass that often suffers from structural failure (lodging) when subjected to wind, rain, and hail. During lodging, excessive lateral deflection occurs, which inherently correlates with the biomechanical properties of stem. As such, fundamental understanding sorghum's behavior required mitigate its propensity for lodging. Herein, we perform creep tests characterize mechanical Della genotype sorghum stems their constituents, i.e., rind pith. This study also examines influence various testing geometries boundary conditions on property characterization. We determine small geometric irregularities typical (e.g., straight circular cylinders) do not affect response in an overall engineering strain sense. However, these lead nonuniform (localized) stresses strains, thereby influencing quantification certain during testing. implement viscoelastic constitutive model describe responses individual constituents (rind pith), as predict stems. find even though carries most load stem itself does show significant time-dependent response, still arising effects