摘要
为定量表征混凝土破坏过程中裂纹扩展及损伤演化规律,借助激光扫描技术与骨料投放算法构建混凝土细观结构模型,结合室内试验,基于连续-非连续单元方法(continuous-discontinuous element method,CDEM)对数值混凝土切面细观模型进行单轴压缩数值模拟。结果表明:模拟所得应力-应变曲线及破坏模式与室内试验吻合较好;混凝土细观损伤演化过程表现为裂纹萌生、扩展、贯通、最终破坏的典型阶段特征,细观破裂度可揭示混凝土在破坏过程中的细观损伤演化规律;分形维数能够定量表征混凝土受压破裂过程中裂纹发展的复杂随机性,sigmoid型演化模型适用于描述混凝土单轴压缩裂纹分形维数的非线性演变过程。
The present work focuses on the quantitative characterization of the crack propagation and damage evolution during concrete failure,a mesoscopic structural model was established by the continuous-discontinuous element method(CDEM)combined with laser-scanning technology as well as aggregate placement algorithm.The simulation results are in good agreement with those of the laboratory experimental results of uniaxial compressive concrete specimens.The mesoscopic damage evolution is described by the typical stage characteristics including crack initiation,propagation,penetration,and final failure.It is also found that the mesoscopic rupture level can reveal the evolution of concrete meso-damage during failure and the fractal dimension can represent the complicated randomness of crack growth of concrete under compressions.Finally,it is found that the sigmoid-type evolution model is suitable to describe the nonlinear process of the fractal dimension of concrete cracks under uniaxial compression.
作者
杨浩杰
张龙飞
李家正
冯吉利
YANG Haojie;ZHANG Longfei;LI Jiazheng;FENG Jili(State Key Laboratory for Geomechanics and Deep Underground Engineering(China University of Mining and Technology(Beijing)),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《中国科技论文》
CAS
北大核心
2023年第6期643-649,655,共8页
China Sciencepaper
基金
国家自然科学基金资助项目(411172116)
深部空间科学与工程研究院基金资助项目(SKLGDUEK202220)。
关键词
混凝土
细观断裂
连续-非连续单元方法
损伤演化
分形维数
concrete
mesoscopic fracture
continuous-discontinuous element method
damage evolution
fractal dimension
