短纤维增强混凝土破坏过程及其尺寸效应数值模拟  

Numerical Simulation of Failure Process and Size Effect of Random Short Fiber Reinforced Concrete

作　　者：张巨功[1] 

机构地区：[1]山西省交通科学研究院,山西太原030006

出　　处：《公路工程》2015年第2期87-91,共5页Highway Engineering

基　　金：国家自然科学基金项目(51308329)

摘　　要：基于细观力学理论建立纤维混凝土细观结构模型,并利用数值模拟技术分析了纤维混凝土单轴受压破坏过程及其尺寸效应。首先将纤维混凝土视为由粗集料、硬化纤维水泥砂浆及两者之间的界面过渡区组成的三相复合材料,然后建立了纤维砂浆延性损伤力学模型和内聚力界面模型。计算结果表明,标准试件的计算结果与实测结果差异较小;纤维混凝土抗压强度随试件尺寸增大而逐渐减小,且变化幅度逐渐降低,峰值后应力应变曲线的下降速率随着试件尺寸增大而加快;尺寸效应是由试件内部断裂裂纹的萌生、扩展和损伤带演化形成过程中应变能的耗散所引起。Mesoscopic structure model of fiber reinforced concrete was established on the basis of mesoscopic mechanics theory in the present study. The failure process and size effect of fiber reinforced concrete under uniaxial compression was analyzed using numerical simulation technology. At first,fiber reinforced concrete was regarded as the integration of three-phase composite materials,such as coarse aggregate,hardened fiber reinforced mortar and the interfacial transition zone between the two. Then the ductile damage mechanics models of fiber reinforced mortar and cohesion interface model were established. The results show that the difference between the calculation result of standard specimen and the measured result is small. The compressive strength of fiber reinforced concrete decreases gradually with the increase specimen size,and the rangeability decreases slowly. The stress-strain curve after the peak value falls sharply with the increase of specimen size. The size effect is caused by the process of strain energy dissipation during the initiation and propagation of fracture crack and evolution of damage zone.

关 键 词：纤维混凝土 尺寸效应 抗压强度 破坏形态 数值模拟 

分 类 号：TU528.01[建筑科学—建筑技术科学]