摘要
断裂过程区的合理表征对于混凝土和岩石等准脆性材料非线性损伤断裂的模拟具有重要意义。本文基于内聚力模型框架,对传统可变形体离散元方法中离散块体的接触界面模型进行改进,引入具有拉断性质的摩尔-库仑屈服面和BK复合能量演化准则,构建能够考虑单拉、拉剪与压剪响应区的非线性界面本构方程,并在分析模型中引入Voronoi镶嵌几何策略以克服断裂扩展路径对离散块体拓扑的依赖性。选择Galvez非对称三点弯梁试验对本文接触界面模型进行验证,计算和试验结果有较好的一致性,充分表明本文模型用于模拟I型和复合断裂问题的适用性。
Reasonable characterization of fracture process zone is key to nonlinear fracture simulation of quasi-brittle materials,such as concrete and rock.This paper,based on a framework of cohesive zone model,presents an extension of the frictional contact model between discrete blocks in the deformable discrete element method.In this model,we adopt a new cracking criterion by combining the mixed-mode BK fracture energy criterion with to the Mohr-Coulomb criterion with tension-cutoff,and formulate nonlinear interface constitutive equations capable of modeling tension-shear and compression-shear mix-mode loading conditions.And Voronoi tessellation is used to eliminate the dependence of fracture propagation paths on the geometric division of discrete blocks.Through parametric analysis of the Galvez asymmetric three-point bending beam tests and adopting suitable softening parameters,we achieve a good agreement between the results of this model and the test data,verifying its capability in simulating uniaxial tension and mixed-mode fractures.
作者
孙建
江汇
何佳龙
周元德
SUN Jian;JIANG Hui;HE Jialong;ZHOU Yuande(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084;Beijing General Municipal Engineering Design&Research Institute Co.,Ltd,Beijing 100082)
出处
《水力发电学报》
EI
CSCD
北大核心
2020年第7期12-20,共9页
Journal of Hydroelectric Engineering
基金
“十三五”国家重点研发计划(2018YFC0406802)
国家自然科学基金(41572251)
关键词
离散元
内聚力模型
Voronoi镶嵌
复合断裂
discrete element method
cohesive zone model
Voronoi tessellation
mixed-mode fracture
