基于真实骨料的细观混凝土建模及数值模拟  

Meso-concrete Modeling and Numerical Simulation Based on Actual Aggregates

作　　者：张龙飞 谢浩 冯吉利[1] 陈燕伟 ZHANG Longfei;XIE Hao;FENG Jili;CHEN Yanwei(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Jinan Rail Transit Group Co.,Ltd.,Jinan 250014,China;School of Qilu Transportation,Shandong University,Jinan 250002,China)

机构地区：[1]中国矿业大学(北京)深部岩土力学与地下工程国家重点实验室,北京100083 [2]济南轨道交通集团有限公司,济南250014 [3]山东大学齐鲁交通学院,济南250002

出　　处：《材料导报》2023年第10期135-142,共8页Materials Reports

基　　金：国家重点研发计划(2016YFC0600901);国家自然科学基金(41172116,U1261212);深部岩土力学与地下工程国家重点实验室(北京)创新基金(SKLGDUEK202220)。

摘　　要：基于激光扫描技术获取真实骨料三维形状,进而构建骨料库,基于“点阵”思想提出了一种新的随机骨料投放算法,借助MATLAB编制了构建三维混凝土细观几何模型的骨料投放程序,所构建的细观模型能够反映混凝土内骨料真实形态、空间分布和级配等细观特征,对三维几何模型进行剖切,即可获得二维平面几何模型,对骨料体积分数为40%的卵石混凝土和骨料体积分数为30%、40%、50%的砾石混凝土典型切面内骨料的粗糙度、圆度和长细比分布特征进行统计分析。利用Python编写接口程序将上述二维切面几何信息导入到ABAQUS中进行网格划分,即可获得混凝土二维细观有限元模型,结合室内实验,基于内聚力模型的连续-非连续数值计算方法研究了不同骨料类型和骨料含量对混凝土单轴压缩破坏的影响规律。此外,该方法还可作为土石混合料、砾岩等具有随机分布特征的复合材料建模和力学性能研究的有效工具。The geometry information of actual aggregates can be obtained by laser scanner to build an aggregate library.Then based on the idea of‘dot matrix’a new random aggregate placement algorithm is proposed,so that a 3D mesoscopic concrete model can be generated,which can truly reflect the shape,distribution and gradation of aggregates in concrete.Simplified 2D plane geometry model was conveniently obtained by cutting the 3D geometry model.The sections of pebble concrete with aggregate content of 40%and gravel concrete with aggregate content of 30%,40%and 50%were made,and the roughness,roundness and elongation ratio of the aggregates in the sections were statistically analyzed.A script was written using Python to import 2D plane geometry information into ABAQUS for meshing.And a 2D finite element model of meso-concrete can be obtained.Combined with the laboratory experiments,the influence of aggregate type and aggregate content on the failure mechanism of concrete was studied by the finite element method with the cohesive zone model,under uniaxial compressions.Moreover,this method is also effective to study the mesoscale model of materials with random distribution characteristics such as soil-rock mixtures and conglomerates.

关 键 词：激光扫描 骨料 混凝土细观模型 骨料投放算法 内聚力模型 

分 类 号：TU528[建筑科学—建筑技术科学]