摘要
颗粒材料具有非连续、离散性等特征,在进行数值模拟时面临着较大的计算压力。通过将精确缩尺准则和粗粒化方法引入到连续-离散耦合(combined finite-discrete element method,FDEM)方法中,旨在为加速基于FDEM的颗粒材料数值模拟提供一种解决方案。基于精确缩尺和粗粒化等理论,推导了FDEM中应遵循的精确缩尺准则,在此基础上分别进行了等粒径颗粒体系及二元颗粒体系的三轴剪切数值试验。试验结果表明,在未引入精确缩尺准则时,粗粒化模型表现的力学响应特征会发生改变,结果出现失真,因此必须对粗粒化模型参数进行修正。引入精确缩尺准则后,粗粒化模型的力学响应特征会得到补正。试验结果论证了FDEM引入精确缩尺准则和粗粒化方法的有效性,即能在近似原始颗粒体系的条件下大幅度提升采用FDEM进行颗粒材料数值模拟的计算效率。基于数值试验结果进行了宏细观力学分析,宏观应力变形和细观接触力相互映证,揭示了精确缩尺和粗粒化方法的细观力学机理。
The particle materials are characterized by discontinuity and dispersion,so they face great computational pressure in numerical simulation.The exact scaling criterion and coarse-grained method are introduced into the combined finite-discrete element method(FDEM)to provide a solution for accelerating the numerical simulation of granular materials based on the FDEM.Based on the theories of exact scaling and coarse granulation,the exact scaling criteria for the FDEM are derived.On this basis,the numerical triaxial shear tests for equal diameter particle system and binary particle system are carried out respectively.The test results show that without the introduction of the exact scaling criteria,the mechanical response characteristics of the coarse-grained model will change,resulting in distortion,and the parameters of the coarse-grained model need to be corrected.After the introduction of the exact scaling criteria,the mechanical response characteristics of the coarse-grained model are corrected.The test results demonstrate the effectiveness of introducing the exact scaling criteria and coarse granulation method into the FDEM.It can greatly improve the computational efficiency of numerical simulation of granular materials using the FDEM under the similar conditions to the original particle system.Based on the numerical test results,the macroscopic stress deformation and mesoscopic contact force are correlated,and the micromechanical mechanism of the exact scaling and coarse-grained methods is revealed.
作者
汪泾周
马刚
赵婷婷
张文宇
胡锦方
周伟
WANG Jingzhou;MA Gang;ZHAO Tingting;ZHANG Wenyu;HU Jinfang;ZHOU Wei(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Institute of Water Engineering Sciences,Wuhan University,Wuhan 430072,China;Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of the Ministry of Education,Wuhan University,Wuhan 430072,China;College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第11期2371-2379,共9页
Chinese Journal of Geotechnical Engineering
基金
国家重点研发计划项目课题(2022YFC3005503)
国家自然科学基金项目(52322907,52179141)
湖北省自然科学基金项目(2022CFD030)
中国电建集团成都勘测设计研究院有限公司资助项目(CD2C20220155)。
