定向钢纤维增强水泥基复合材料准脆性断裂分析  

Analysis on quasi-brittle fracture performanceof aligned steel fiber reinforced cement-based composites

作　　者：慕儒 王晶晶 卿龙邦 李杨 管俊峰 Mu Ru;Wang Jingjing;Qing Longbang;Li Yang;Guan Junfeng(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;School of Civil Engineering,Tianjin Chengjian University,Tianjin 300384,China;School of Civil Engineering and Communication,North China University of Water Resources and Electric Power,Zhengzhou 450045,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]天津城建大学土木工程学院,天津300384 [3]华北水利水电大学土木与交通学院,郑州450045

出　　处：《东南大学学报（自然科学版）》2024年第2期294-302,共9页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(52022027);河北省自然科学基金资助项目(E2022202141,E2023202268);河北省高层次人才资助项目(A202101011)。

摘　　要：基于边界效应模型基本理论,建立了钢纤维长度与特征裂缝长度之间的关系,计算了定向钢纤维增强水泥基复合材料(ASFRC)的等效断裂韧度和拉伸强度,进而得到了ASFRC材料的断裂破坏曲线.结果表明,当离散系数分别取0.4~0.7和0.2~0.4时,可得到较为合理的等效断裂韧度和拉伸强度值.对比分析ASFRC和随机乱向钢纤维增强水泥基复合材料(SFRC)的断裂破坏曲线可以发现,满足线弹性断裂力学的最小试件尺寸随着离散系数的增大而增大;ASFRC和SFRC的拉伸强度和考虑初始裂缝影响的名义应力随着离散系数的增大而减小.此外,改进的简化解析公式不仅可确定材料的等效断裂韧度和拉伸强度,还可预测试件的破坏.Based on the basic theory of the boundary effect model,the relationship between steel fiber length and characteristic crack length was established,thus the equivalent fracture toughness0x0E䥺Symbol`@@0x0Fand tensile strength of aligned steel fiber reinforced cement-based composites(ASFRC)were calculated,and then fracture failure curves of ASFRC were obtained.The results show that more reasonable values of the equivalent fracture toughness and tensile strength can be obtained when the discrete number is taken as 0.4-0.7 and 0.2-0.4,respectively.Comparing the fracture failure curves of ASFRC and steel fiber reinforced cement-based composites(SFRC),it can be found that the minimum specimen size satisfying linear elastic fracture mechanics increases with the increase of the discrete number.In addition,the tensile strength and the nominal stress considering the influence of the initial crack length of ASFRC and SFRC decrease with the increase of the discrete number.Furthermore,the improved simplified analytical formulas can not only determine the equivalent fracture toughness and tensile strength,but also predict the damage of the specimens.

关 键 词：定向钢纤维增强水泥基复合材料 边界效应模型 等效断裂韧度 拉伸强度 断裂破坏曲线 

分 类 号：TU528[建筑科学—建筑技术科学]