基于格构离散单元法的准脆性材料断裂研究  

Fracture analysis of quasi-brittle materials based on lattice discrete element method

作　　者：刘摇 周伟[1] 王桥[1] 马刚[1] 田文祥[1] 陈凌霄 高宇 LIU Yao;ZHOU Wei;WANG Qiao;MA Gang;TIAN Wenxiang;CHEN Lingxiao;GAO Yu(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China;Datang Xuanwei Hydropower Development Co.,Ltd.,Xuanwei 655400,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]大唐宣威水电开发有限公司,云南宣威655400

出　　处：《武汉大学学报（工学版）》2022年第3期211-219,共9页Engineering Journal of Wuhan University

基　　金：国家重点研发计划项目(编号:2016YFC0401909,2016YFC0401907);国家自然科学基金项目(编号:51979207)。

摘　　要：为了更好地理解准脆性材料在工程应用中的失效机理,需要不断改进测试方法和分析工具。使用具有极高计算效率的格构离散单元法(lattice discrete element method,LDEM)对准脆性材料进行建模,该方法采用双线性本构模型数值分析,利用杆单元的失效去除来模拟裂纹的萌生与扩展。经验证可见,LDEM受网格划分的影响较小。通过与经典断裂实例的对比可见,格构离散单元法在准脆性材料裂纹扩展模拟上与前人研究有较好的一致性。利用格构离散单元法模拟3D打印的聚苯乙烯切口梁的三点弯曲试验,得到了与物理试验相一致的荷载-位移曲线及裂纹扩展模式,证明了LDEM在模拟准脆性材料断裂问题上的合理性与高效的计算效率。该方法在百万级甚至更多单元大规模数值计算模拟上有很大潜力。In order to better understand the failure mechanism of quasi-brittle materials in engineering applications,it is necessary to continuously improve the test methods and analysis tools.In this paper,the lattice discrete element method(LDEM)with high computational efficiency is used to model the quasi-brittle materials.The bilinear constitutive model is used for numerical analysis,and the failure of truss element is used to simulate the initiation and propagation of cracks.It is verified that the method is less affected by mesh generation.By comparing with the classical fracture examples,it is found that the LDEM is in good agreement with the previous studies in the simulation of crack propagation of quasi-brittle materials.This paper also uses the LDEM to simulate the three-point bending experiment of a 3 D printed polystyrene notched beam,and obtains the loaddisplacement curve and crack growth mode consistent with the physical experiment,which proves the rationality of the LDEM in simulating the fracture problem of quasi-brittle materials and the high efficiency of the LDEM.This method has great potential in large-scale numerical simulation of millions or more elements.

关 键 词：断裂力学 格构离散单元法 准脆性材料 裂纹扩展 3D打印 三点弯曲 大规模数值计算 

分 类 号：O341[理学—固体力学]