摘要
为了在细观层次上研究混凝土梁的损伤断裂机理,将混凝土视为由骨料、水泥砂浆和界面组成的三相复合材料。基于三维随机骨料随机力学参数模型,建立了2个混凝土梁湿筛试件的数值模型;模型MX1模拟骨料的随机分布,模型MX2在MX1的基础上模拟混凝土各相材料参数的随机性,通过这2个模型的抗弯数值试验,展现了混凝土梁损伤断裂和裂缝萌生与扩展的渐进过程。结果表明:数值试验得到的混凝土梁弯拉强度与真实试验测得的弯拉强度较为接近;由于骨料分布的随机性,混凝土裂纹起裂和扩展表现出显著的不规则性和不连续性;受材料参数随机分布的影响,模型MX2较MX1承载力略有降低,变形稍有增加。
In order to discuss the damage and fracture mechanism of concrete beam on the meso- level, the concrete was considered as a three-phase composite material consisting of aggregates, mortar and bonding material. Two numerical models of wet sieved concrete beam specimens were established based on the 3-D random aggregate and random mechanical parameter model. The model MX1 only simulated the random distribution of aggregate, while the model MX2 simulated the random distribution of concrete material parameters. By the flexural numerical test of the two models, the gradual process of damage and fracture, as well as the crack appearance and growth of concrete was simulated. Result shows that the flexural strength of concrete by numerical test approximates to that by physical test. The generating and expanding of crack in concrete beam reveal remarkable abnormity and discontinuity because of the random distribution of aggregate. Influenced by the random distribution of material parameters, the bearing capacity of model MX2 is slightly lower than that of model MX1, and the displacement of model MX2 is mildly larger than that of model MX1.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2010年第2期50-55,共6页
China Journal of Highway and Transport
基金
"十一五"国家科技支撑计划项目(2006BAJ15B03-01)
关键词
桥梁工程
混凝土梁
数值试验
细观数值模型
随机力学参数
损伤断裂
随机骨料
bridge engineering
concrete beam
numerical test
mesoscopic numerical model
ran-dom mechanical parameter
damage and fracture
random aggregate
