Optimal tip shape for minimum drag and lift during horizontal penetration in granular media
Optimal tip shape for minimum drag and lift during horizontal penetration in granular media
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DOI：
10.2139/ssrn.4247930
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发表时间：
2023-05
期刊：
影响因子：
5.7
通讯作者：
F. Patino-Ramirez;C. O’Sullivan
中科院分区：
文献类型：
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作者：
F. Patino-Ramirez;C. O’Sullivan
颗粒介质中的水平渗透是普遍存在的，从隧道和岩土工程现场勘察，到自然界中的根系生长和穴居动物的运动。这一贡献耦合离散元法（DEM）与蚁群优化，一种启发式优化算法，找到最佳的尖端形状，以尽量减少阻力和升力在水平穿透。最大限度地减少阻力的尖端具有细长的轮廓，尖端曲率较低，与传统CPT入侵者相比，阻力降低了15.6%，但是这种形状会引起向下的力，该力随着入侵者深度而增加。相反，使升力最小化的尖端是钝的，具有高尖端曲率和短宽度，并且与CPT相比，阻力和升力分别减少4.5%和30.8%。升力和阻力是相互竞争的优化目标，因此，可以使用帕累托最优性来建立具有阻力和升力之间的最佳权衡的叶尖形状。帕累托最优尖端形状分别使阻力和升力降低了10.7%和19.4%，并且与沙鱼的轮廓非常相似。这一贡献表明，当一个共同的目标存在，生物启发的解决方案可以提供一个最佳的解决方案，工程应用。我们还展示了在优化框架内集成DEM模拟以开发创新设计解决方案的潜力。
Horizontal penetration in granular media is ubiquitous, from tunneling and geotechnical site investigation, to root growth and the locomotion of burrowing animals in nature. This contribution couples the discrete element method (DEM) with ant colony optimisation, a heuristic optimisation algorithm, to find the optimal tip shapes to minimise drag and lift forces during horizontal penetration. The tip which minimizes drag has a slender profile with a low tip curvature, to give a drag force that is $$15.6\%$$ 15.6 % lower compared to a conventional CPT intruder, however this shape induces a downwards force that increases with intruder depth. Conversely, the tip that minimizes lift is blunt, with a high tip curvature and short width, and reduces the drag and lift forces by $$4.5\%$$ 4.5 % and $$30.8\%$$ 30.8 % (respectively) compared to the CPT. The lift and drag forces are competing optimisation objectives, thus the tip shape with the optimal trade-off between drag and lift forces can be established using Pareto optimality. The Pareto optimal tip shape reduces the drag and lift forces by $$10.7\%$$ 10.7 % and $$19.4\%$$ 19.4 % respectively, and is strikingly similar to the profile of a sandfish. This contribution shows that when a common goal exists, bio-inspired solutions can offer an optimal solution to engineering applications. We also show the potential to integrate DEM simulations within an optimization framework to develop innovative design solutions.