摘要
细观力学建模是研究混凝土宏观力学性能的有效手段。采用ABAQUS有限元软件以及cohesive内聚力单元,建立了嵌入内聚力单元的混凝土三维细观模型,模拟了静态及动态压缩下混凝土试件的开裂过程,并与试验加载得到的各阶段裂纹扩展状态进行了对比验证。在有效数值模型的基础上建立了基于内聚力单元的脆性断裂本构关系,并计算了损伤演化值。研究结果表明:不同破坏阶段的模型应力变化特征明显,与混凝土的宏观强度基本相符;不同组分的破坏模式差异显著,且内部骨料开始破坏时的抗压强度最高,数值模拟所得的混凝土试件破坏状态与试验结果基本一致;通过基于能量参数的指数型演化方式对损伤变量进行了计算,验证了基于脆性断裂的本构模型可有效预测混凝土试件的破坏过程。
Modeling by micromechanics is an effective means to study the macroscopic mechanical properties of concrete.By using the ABAQUS finite element software and cohesive element,a three-dimensional mesoscopic model of concrete specimen with random aggregate distribution was established to simulate the failure state of concrete specimens under static and dynamic compression,and the crack growth state of each stage was compared with that obtained by experimental loading.Based on the effective numerical model,the differences of peak intensity and crack propagation under different loading rates were studied,and the damage evolution value was calculated.The results showed that the stress variation characteristics of the models at different stages were obvious,which were basically consistent with the macroscopic strength of concrete.The failure modes of different components were obviously different,and the compressive strength of internal aggregate was the highest at the beginning of failure.The failure state obtained by numerical simulation was basically consistent with the test results.The damage variables were calculated by the exponential evolution method based on energy parameters,and it was verified that the constitutive model based on brittle fracture could effectively predict the failure process of concrete specimens.
作者
田亮
孟俊良
赵健
樊立龙
王宇宁
张诚至
TIAN Liang;MENG Junliang;ZHAO Jian;FAN Lilong;WANG Yuning;ZHANG Chengzhi(Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,Tianjin Chengjian University,Tianjin 300384,China;CRCC Bridge Engineering Bureau Group Co.,Ltd.,Tianjin 300300,China;Department of Civil Engineering,Tsinghua University,Beijing 100084,China)
出处
《工业建筑》
2024年第9期170-176,共7页
Industrial Construction
基金
国家自然科学基金项目(51708346)
中国铁建股份有限公司科技重大专项(2020-A01)
天津市企业科技特派员项目(22YDTPJC00210)
天津市科技开发项目(19YDLZSF00030)。
关键词
三维细观模型
内聚力单元
脆性断裂
本构关系
损伤演化
three-dimensional mesocopic models
cohesive unit
brittle fracture
constitutive relations
damage evolution
作者简介
第一作者:田亮,博士,副教授,主要从事高性能混凝土及钢桥结构方面的研究。电子信箱:sjtu_tl@126.com。
