定向钢纤维增强水泥基复合材料准脆性断裂分析OA北大核心CSTPCD

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 toughness and 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,re-spectively.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 tough-ness and tensile strength,but also predict the damage of the specimens.