Dynamic Tensile Performance And Numerical Simulation Of Steel Fiber Reinforced Concrete

In face of more and more unpredictable natural disasters, the increasingly high demand for high-performance materials, construction projects in order to strengthen security, increase dynamic impact of concrete building structures, seismic wind resistance is the key which is extremely important. In order to strengthen the security of the construction, it is made a series research of experiments and related theoretical studies to SFRC dynamic tensile mechanical properties. The major contents are followings:First, using SHPB steel fiber volume fraction containing0、2%、3%of the concrete block for dynamic splitting tensile test. The results show that the strength static is1.22to1.51times to the splitting tensile strength, and it increased41.60%and68.22%than the non-steel fiber concrete block. The results also show that, the higher steel fiber content, the less cracking numbers and the smaller the cracks. The final cracking due to lack of strength between steel fiber and adhesive mortar, and the steel fiber is pulled out, rather than the strength of steel fiber itself is enough to pull off.It is established that the relationship between SFRC dynamic splitting tensile strength and the matrix. And it also established relationship between SFRC dynamic splitting tensile strength and bullet impact velocity of bullet.Second, the dynamic impact on the SFRC splitting numerical simulation was made by using the finite element method. It shows that the internal force transient changes, failure modes and features under the conditions of the high-speed impact by computer. Strain rate were changed from the size and strength of concrete to proceed compared and analyze the difference, then validate the test conclusion:first, the dynamic tensile strength of concrete can be improved with the increase of strain rate; second, as the concrete strength increases, resistance to dynamic impact is stronger role for the further understanding of its impact damage characteristics provides a reference. Third, with the help of the combination of the experimental results and modeling phenomenon, the dissipation of energy on the SFRC cracking process is researched and made exploration, and analyzes the impact of various parameters on the fracture model, then applied the concrete energy dissipation principle to the design of steel fiber concrete structural, deducted the energy in the structural design of bending moment, combined the SFRC dynamic performance with actual engineering applications closely.