DEM study of the alteration of the stress state in granular media around a bio-inspired probe
DEM study of the alteration of the stress state in granular media around a bio-inspired probe
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DOI：
10.1139/cgj-2021-0260
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发表时间：
2022-03-07
影响因子：
3.6
通讯作者：
DeJong, Jason
中科院分区：
文献类型：
--
作者：
Chen, Yuyan;Martinez, Alejandro;DeJong, Jason
土壤渗透是岩土工程中普遍存在的能量密集型过程，其通常通过准静态推动、冲击驱动或挖掘来完成。相比之下，海洋和蚯蚓，剃刀蛤和植物等生物已经开发出有效的渗透策略。使用这些生物体的启发运动序列，一个探头，使用一个自包含的锚，以产生所需的反作用力，以推进其尖端到更大的深度已经概念化。本研究探讨此探头和粗粒土之间的相互作用，使用三维离散元建模。土壤有效应力的空间分布表明，锚的膨胀产生的主有效应力的旋转和旋转，有利于通过诱导周围的应力松弛探针的尖端和周围的应力增加锚的渗透。空间应变图突出了探头周围的体积变形，而应力和应变的测量结果表明，周围的锚和尖端的土壤的状态演变的关键州线。在随后的头端推进过程中，应力和应变与初始插入过程中的应力和应变相似，导致头端阻力的重新活动。较长的锚和较短的锚-头端距离通过在头端前方产生更大的应力松弛更好地促进头端推进。
Soil penetration is a ubiquitous energy-intensive process in geotechnical engineering that is typically accomplished by quasi -static pushing, impact driving, or excavating. In contrast, organisms such as marine and earthworms, razor clams, and plants have developed efficient penetration strategies. Using motion sequences inspired by these organisms, a probe that uses a self-contained anchor to generate the reaction force required to advance its tip to greater depths has been conceptualized. This study explores the interactions between this probe and coarse-grained soil using 3D discrete element modeling. Spatial distributions of soil effective stresses indicate that expansion of the anchor produces arching and rotation of principal effec-tive stresses that facilitate penetration by inducing stress relaxation around the probe's tip and stress increase around the anchor. Spatial strain maps highlight the volumetric deformations around the probe, while measurements of both stresses and strains show that the state of the soil around the anchor and tip evolves toward the critical state line. During subsequent tip advancement, the stresses and strains are similar to those during initial insertion, leading to the remobilization of the tip resistance. Longer anchor and shorter anchor-to-tip distance better facilitate tip advancement by producing greater stress relaxation ahead of the tip.