Effect of Rotation on Seeds’ Self-Burial Process: Insights from DEM Simulations
Effect of Rotation on Seeds’ Self-Burial Process: Insights from DEM Simulations
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DOI：
10.1061/9780784482834.032
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发表时间：
2020-02
期刊：
影响因子：
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通讯作者：
Y. Tang;S. Huang;J. Tao
中科院分区：
文献类型：
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作者：
Y. Tang;S. Huang;J. Tao
一些开花植物的种子，如牛筋草和天竺葵，可以把自己埋在地下，以便将来发芽。由于芒的吸湿卷曲和展开，实现了自埋行为。据推测，由于芒的螺旋结构的变化而引起的旋转运动通过打破土壤中的局部力链来降低种子的穿透阻力。在这项研究中，这一假设进行了测试，使用DEM模型，它允许调查之间的相互作用的穿透和颗粒材料在不同的尺度。DEM模型首先使用现有的实验室三轴试验数据的渥太华砂校准和验证。然后将圆锥体以不同的转速垂直穿透到校准的土壤样品中。据观察，旋转运动可以显着降低穿透阻力，并且在较高的旋转速度下，降低变得更加明显。从颗粒尺度分析出发，研究了土样的力链和颗粒速度场，并进行了实例对比，揭示了减薄效果的基本机理。
Seeds of some flowering plants such asErodiumandPelargoniumcan bury itself into the ground for future germination. The self-burial behavior is realized due to hygroscopic coiling and uncoiling of the awns. It is hypothesized that the rotating motion due to the changing of the helical structure of the awn reduces penetration resistance of the seed via breaking the local force chains in soil. In this study, this hypothesis is tested using a DEM model, which allows investigating the interaction between a penetrator and the granular material at different scales. The DEM model was first calibrated and validated using existing laboratory triaxial test data of Ottawa sand. A cone was then penetrated into the calibrated soil sample vertically with different rotational speeds. It was observed that the rotational movement can significantly reduce the penetration resistance, and the reduction becomes more pronounced at higher rotational speeds. From particle scale analysis, the force chain and particle velocity field of the soil sample were investigated, and comparisons were made among cases, which shed light on the fundamental mechanism of the reduction effect.