混凝土弯曲拉伸力学性能及尺寸效应细观数值研究  

Mesoscopic simulation on the mechanical properties and size effect of concrete beams subjected to flexural tensile loading

作　　者：杜敏[1] 赵彦[1] 陈凡红 王素莉[1] DU Min;ZHAO Yan;CHEN Fanhong;WANG Suli(Institute of Disaster-prevention Science and Technology,Langfang 065201,China;Yanching Institute of Technology,Langfang 065201,China)

机构地区：[1]防灾科技学院,河北廊坊065201 [2]燕京理工学院,河北廊坊065201

出　　处：《混凝土》2022年第2期67-70,共4页Concrete

基　　金：国家自然科学基金(51408127)。

摘　　要：为反应骨料颗粒细观组分对混凝土弯曲拉伸宏观力学行为的影响,建立混凝土随机骨料细观尺度力学模型,细观组分材料采用塑性损伤和线弹性本构关系,开展混凝土弯曲拉伸细观尺度数值模拟,探讨骨料颗粒的影响机理,并与混凝土弯曲拉伸试验进行对比。研究显示:(1)混凝土细观数值模型能较好地模拟混凝土在弯曲拉伸荷载下的宏观力学行为。(2)弯曲拉伸损伤从模型底部薄弱的界面过渡区形成,并向砂浆基质延伸。骨料粒径越大,损伤路径相对越曲折。(3)随着骨料粒径的减小,混凝土弯曲抗拉强度略有提高,尺寸效应现象更为显著。Considering the impact of aggregate particles,the random aggregate model was set up,composed by the aggregate,mortar matrix and interface transition zone.The plasticity damaged model was adopted to describe the mechanical properties of mortar matrix and interface transition zone,then the linear elastic model was adopted to describe the mechanical properties of aggregate particles.The numerical simulation of concrete under flexural tensile loading was carried out,and the influence mechanism of aggregate particles was discussed.At the end,the simulated results were compared with test data.The results showed that the mechanical behavior of concrete under flexural tensile load can be simulated by the microscopic numerical model.The damage area is formed from the weak interfacial transition zone at the bottom of the model.Then,the damage area extends to the mortar matrix.When the aggregate size increased,the damage path becomes tortuous for the model.The flexural tensile strength decreases,and the size effect is more apparent for concrete samples with smaller size aggregate.

关 键 词：混凝土 弯曲抗拉强度 尺寸效应 骨料粒径 

分 类 号：TU528.01[建筑科学—建筑技术科学]