三维离散元大尺度模拟中变粒径方法的优化及其应用

发布时间：2018-06-22 05:03

本文选题：离散元模拟 + 变粒径　；参考：《岩土工程学报》2017年01期

【摘要】：在已有的变粒径建模方法基础上,针对不同粒径区宏观弹性不一致和界面区大小颗粒互相渗入两个问题进行优化。通过在近场核心区域采用小粒径颗粒模拟真实土颗粒,远场边界区域逐级放大颗粒粒径,不同粒径之间采用相同密实度的混合粒径模拟,实现三维大尺度离散元模拟,以减少模拟颗粒数量提升运算速度。基于宏观弹性一致条件,建立静力条件下几何上等比例放大颗粒体系的颗粒材料参数尺度关系,并满足应力、应变和应变能一致性,通过三轴模拟验证了宏观弹性一致性。在变粒径交界处设置密实度与均一颗粒区一致的混合层有效防止大小颗粒互相渗入,变形特性与均一颗粒区趋于一致,并提出了两种粒径颗粒混合生成特定密实度的方法。最后,通过模拟静力触探试验(CPT),表明该方法的有效性。该方法可为三维离散元模拟工程大尺度问题提供新途径。
[Abstract]:Based on the existing modeling methods of variable particle size, the macroscopic elastic inconsistency of different particle size regions and the infiltration of interfacial particle size into each other are optimized. In the near field core region, small particle size is used to simulate the real soil particle, the far field boundary area is enlarged step by step, and the mixed particle size is simulated with the same compactness between different particle sizes to realize the simulation of three dimensional large scale discrete element. To reduce the number of simulated particles to improve the operation speed. Based on the macroscopic elastic consistency condition, the parameter scale relation of the particle material in the static condition is established, and the consistency of stress, strain and strain energy is satisfied. The macroscopic elastic consistency is verified by triaxial simulation. At the junction of variable particle size, the mixing layer with the consistency of density and homogeneous particle area can effectively prevent the size particles from infiltrating into each other, and the deformation characteristics tend to be consistent with the uniform particle region. Two methods of mixing particle size to produce specific density are put forward. Finally, the effectiveness of the method is demonstrated by simulating the static penetration test (CPT). This method can provide a new approach for 3D discrete element simulation of large scale engineering problems.
【作者单位】：上海海事大学海洋科学与工程学院;中交上海航道勘察设计研究院有限公司;
【基金】：国家自然科学基金青年基金项目(51208294) 上海市教委一流学科建设项目;上海市教委科研创新项目(15ZZ081) 2013年上海市研究生教育创新计划实施项目(20131129) 上海海事大学学术创新团队(A2-0201150404)
【分类号】：TU43

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