混凝土二维干缩开裂分析的改进弥散裂纹模型  

TWO DIMENSIONAL ANALYSIS OF DRYING SHRINKAGE MICRO-CRACKING IN CONCRETE WITH MODIFIED SMEARED CRACKING MODEL

作　　者：李曙光[1] 李庆斌[1] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《工程力学》2011年第12期65-71,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(90715041);十一五支撑计划项目(2008BAB29B05)

摘　　要：现有弥散裂纹模型在模拟混凝土细观干缩开裂时,存在收敛性差、易出现裂纹"误判"的局限。针对此不足,该文提出了等效断裂能开裂破坏准则,用以改进弥散裂纹模型;并应用允许材料破坏的有限元显式解法,模拟了单骨料、随机骨料结构混凝土试件的二维干缩开裂,所得裂纹分布与对比试验观察结果基本吻合,显示了改进弥散裂纹模型在混凝土干缩开裂模拟中的适用性。The traditional fracture energy cracking criterion in a smeared cracking model,with the limitation of poor convergence and misjudgement of micro-cracks,is not applicable in the meso-level simulation of drying shrinkage micro-cracking in concrete.A modified smeared cracking model with an equivalent fracture energy cracking criterion is proposed and employed in the simulation of drying shrinkage micro-cracking in concrete specimens using an explicit method available in the commercial software ABAQUS.The micro-crack patterns from simulations of single-aggregate and random-aggregate-structure specimens agree well with the experimental results,showing the applicability of the modified smeared cracking model in modeling the meso-level drying shrinkage micro-cracking in concrete.

关 键 词：混凝土 干缩微裂纹 细观层次 等效断裂能 弥散裂纹 显式解法 

分 类 号：TU528.01[建筑科学—建筑技术科学]