摘要
基于"基面力"概念及势能原理,给出任意三角形单元刚度矩阵及应变显式表达式。根据不同取代率的再生混凝土的细观结构特征,建立再生骨料取代率为0、25%、50%、75%、100%的二维任意多边形随机骨料模型,研究再生混凝土细观裂缝开展机理及抗拉强度。结果表明:基于"基面力"概念的新型有限元算法-"基面力元法",可以用于非均质材料的细观损伤及断裂机理研究;在圆形骨料内部生成基框架并延伸建立凸型骨料,效率高、更符合天然骨料形状;随着再生骨料取代率的增加,裂纹主要围绕再生骨料分布,裂纹扩展更随机,抗拉强度逐渐降低;位移加载时,内部微裂纹首先出现在新黏结带区域,随后向骨料尖端发展并贯穿新老砂浆,最终在骨料密集区域形成横向贯穿破坏裂缝。
Based on the concept of base force and the potential energy principle,the explicit expression of triangular element stiffness matrix and element strain was given.According to the meso-scopic structure of recycled aggregate concrete,the random convex polygon aggregate model with different recycled aggregate replacement ratios of0,25%,50%,75%and100%were established to research the mechanism of meso-scopic cracks and the tensile strength.The results shows that the new finite element method based on the concept of base force can be used to research the meso-damage and fracture mechanism of heterogeneous materials;The base frame was established inside the round aggregate and then extended to convex aggregate,the method is efficiency and the aggregate shape is more in line with natural aggregate;Along with the increase replacement ratios of recycled aggregate,the cracks were mainly distributed around the recycled aggregate,the cracked extension were more randomly and the uniaxial tensile strength were decreased gradually;The internal meso-cracks first appeared in the old ITZ,then to the tip of aggregate and through the new and old cement mortar,the cracks expanded to destructive cracks in the aggregate intensive areas eventually.
作者
王耀
赵华玮
胥民尧
纵岗
褚昊
WANG Yao;ZHAO Huawei;XU Minyao;ZONG Gang;CHU Hao(College of Architecture and Civil Engineering,Yancheng Vocational Institute of Industry Technology,Yancheng 224005,China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《混凝土》
CAS
北大核心
2018年第11期17-21,共5页
Concrete
基金
国家自然科学基金(11172015)
2017年江苏省高校优秀科技创新团队
盐工院自然科学重点课题(ygy1603
ygy1705)
关键词
基面力
再生骨料取代率
数值模拟
细观裂缝
base force
recycled aggregate replacement ratios
numerical simulation
meso-crack
