摘要
采用随机生成算法投放钢纤维,建立了随机乱向、定向钢纤维增强水泥基复合材料(SFRC、ASFRC)三点弯曲梁细观有限元数值模型,计算了不同纤维掺量下SFRC试件和ASFRC试件加载断裂的全过程,分析了三点弯曲梁开裂截面处的纤维应力,研究了定向钢纤维的细观增强机理.结果表明:SFRC试件和ASFRC试件荷载-裂缝张开口位移全曲线的模拟值与试验值符合较好,峰值荷载的误差在10%以内;SFRC试件和ASFRC试件的峰值荷载与纤维合力的最大值均随着纤维掺量的增加而增大,当纤维掺量为0.8%、1.2%、2.0%时,ASFRC试件的峰值荷载较SFRC试件提高了75%、111%、141%,纤维合力的最大值较SFRC试件增大了202%、144%、127%;定向钢纤维可以有效改善水泥基复合材料的断裂性能,显著提高钢纤维的利用率,延缓裂缝的扩展.
A random generation algorithm was used to steel fiber, and then the meso-scale finite element numerical mode of three point bending beam of random and aligned steel fiber reinforced cementitious composites(SFRC, ASFRC) were established. The whole process of loading and fracture of SFRC specimens and ASFRC specimens with different fiber contents were calculated. The fiber stress at the cracked section of the three point bending beam was analyzed, and the meso-scale reinforcement mechanism of aligned steel fiber was studied. The results show that the whole load-crack opening displacement curves of SFRC specimens and ASFRC specimens obtained from test and numerical simulation are in good agreement and the error of the peak load is within 10%. The peak load and the maximum fiber force of the two kinds of specimens both increase with the increase of fiber content. When the fiber content is 0.8%, 1.2% and 2.0%, the peak load of ASFRC specimens increased by 75%, 111% and 141% compared to SFRC specimens, and the maximum fiber force of ASFRC specimens increased by 202%, 144%, and 127%compared with SFRC specimens. Aligned steel fiber can effectively improve the fracture performance of cementitious composites, significantly increase the fiber efficiency, and delay the propagation of cracks.
作者
卿龙邦
杨子美
慕儒
张金鑫
籍晓凯
QING Longbang;YANG Zimei;MU Ru;ZHANG Jinxin;JI Xiaokai(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China)
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2023年第2期111-121,共11页
Journal of Building Materials
基金
国家自然科学基金资助项目(52022027,52078180)
河北省自然科学基金资助项目(E2022202141,E2020202151)
河北省高等学校科学技术研究重点项目(ZD2019072,ZD2020190)。
关键词
钢纤维
水泥基复合材料
细观数值模拟
等效应力-应变关系
增强机理
steel fiber
cementitious composite
meso-numerical simulation
equivalent stress-strain relationship
enhancement mechanism
