关键词: 钢纤维混凝土;钢纤维效应;本构关系;增强增韧

Abstract: The material quasi-static mechanics performance experiments of steel fiber reinforced concrete with the fiber volume ratio of 0％, 0.75％, 1.5％, 3％, 4.5％ and 6％ were carried out to obtain the stress-strain curves under the same strain rate .Based on the phenomenological theory of the experimental results showed that with the increase of fiber content , the peak strain and the peak stress of the steel reinforced concrete are increased, and the strain softening after the peak stress was observed .Based on the assumption that there are two independent factors to control the nonlinear behavior of the steel fiber reinforced concrete, one is related to strain to indicate the nonlinear stress -strain behavior and the other is related to the fiber volume ratio to express the fiber content effect , a new type of constitutive equation is proposed.The details how to get the equation and the material parameters is discussed completely and the least squares optimization numerical simulations were used to fit the experiment curves .Good agreement between numerical simulations and experiment curves is achieved and hence , it is of great significance for the reasonable design of steel fiber concrete in practical engineering .

Key words: Steel Fiber Reinforced Concrete (SFRC);fiber content effect;constitutive relation;enhanced and toughening