基于三维晶质模型-离散元法的数值模拟研究:动态弯曲拉伸强度试验中的多级力链网络分析
A numerical study based on GBM3D-DEM model:Multi-level force chain analysis in dynamic flexural tensile strength test
范豆豆 1张涛 1蔚立元 1胡李华 1苏海健 1魏江波2
作者信息
- 1. State Key Laboratory of Intelligent Construction and Healthy Operation&Maintenance of Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China
- 2. College of Geology and Environment,Xi'an University of Science and Technology,Xi'an 710054,China
- 折叠
摘要
力链网络是岩石材料加载下的关键信息,类似岩石的微观裂纹和宏观力学行为.本文提出了一种基于离散元法(GBM3D-DEM)的三维晶质模型,采用耦合的(有限差分法(FDM)-离散元(DEM))霍普金森压杆系统模拟了动态弯曲拉伸强度试验.结果表明,加载过程中试样内部所有一般力链(GF)的值和数量分别表明了样品的应力水平和裂纹活动.强力链(HF),作为那些在峰值荷载下大于所有一般力链(GF)平均值的力链,其数量可以更深入地表征施加在试样两端的应力水平.同时,强力链的主要倾向分布方向与加载方向一致,并垂直于裂纹的加载方向.本文将力链网络进行了多级分类,并对花岗岩的裂纹活动和力学行为进行了研究,并从多级力链网络的角度分析了加载率效应.
Abstract
The force chain network is the key information of rock materials under loading,which is close to the micro-scale cracking and macroscopic mechanical behavior of rocks.In this paper,a novel 3D grain-based model based on the discrete element method(GBM3D-DEM)is proposed to reproduce the heterogeneous structure of granites,and the dynamic flexural tensile strength test is simulated by the coupled(finite difference method(FDM)-DEM)split Hopkinson pressure bar(SHPB)numerical system.The results show that the value and the number of all general force chains(GF)inside the sample during the loading process indicate the stress level and cracking activity of the sample respectively.The number of high-strength force chains(HF),defined as those with values greater than the average value of all GF at peak load moment,can deeper characterize the stress level applied on both ends of the sample.Also,the main orientation distribution of HF is consistent with the loading direction and is perpendicular to that of cracks.In general,the force chain network is multi-level classified and the cracking activity and mechanical behavior of granite has been investigated from a microscopic perspective.The loading rate effect is also analyzed from the multi-level force chain network perspective.
关键词
岩石力学/三维晶质模型/耦合霍普金森压杆系统/多级力链网络/加载率效应Key words
rock mechanics/3D grain-based model/coupled SHPB system/multi-level force chain network/loading rate effect引用本文复制引用
基金项目
National Natural Science Foundation of China(52179118)
National Natural Science Foundation of China(42077240)
National Natural Science Foundation of China(52009016)
出版年
2023
NETL
NSTL
维普
万方数据