Three Dimensional Numerical Simulation Of Anti-penetration Performance Of Steel Fiber Reinforced Concrete Component

Steel fiber reinforced concrete structure has excellent mechanical properties and impact resistance,penetration ability,it has been widely used in civil buildings,roads,and defence construction.The failure mechanism and failure process of steel fiber reinforced concrete structures are very complex under the high strain rate loading,such as impact and explosion,the research on its impact and penetration is still under development.In this paper,the dynamic failure principle of steel fiber reinforced concrete structure is discussed,the dynamic strength index of steel fiber reinforced concrete is introduced into the HJC model,and the explicit stress updating algorithm of HJC model is proposed,with the aid of ABAQUS software,the numerical simulation of high speed impact steel fiber reinforced concrete slab was carried out.The main work and conclusions are as follows:(1)The mechanical properties of steel fiber reinforced concrete are introduced.The failure process of concrete structure,the transfer of force in steel fiber reinforced concrete and the reinforcing mechanism and crack resistance effect of steel fiber in the matrix are discussed.(2)Based on the analysis of the dynamic test data and the constitutive model of steel fiber reinforced concrete,overall dynamic strengthening effect of steel fiber reinforced concrete,the dynamic reinforcement parameters of steel fiber reinforced concrete are introduced into the HJC constitutive model of concrete,and the conventional HJC model is modified.The modified HJC model considering the response of steel fiber on the strength and strain rate of the matrix material,it provides an effective way and method for the numerical analysis of high impact resistance and penetration of steel fiber reinforced concrete.Due to the complexity of the problem and the limitation of the test data,the research in this field needs to be further developed.(3)Considering the characteristics of impact and penetration of projectile on steel fiber reinforced concrete,an explicit stress updating algorithm for HJC model isdeveloped,using ABAQUS/Explicit user subroutine,the corresponding calculation program is compiled,the failure criterion of the material element and the treatment method of the unit after failure are determined,it provides an effective method for the simulation of the high speed impact and penetration of steel fiber reinforced concrete.(4)By using the program and the treatment method of the concrete unit,ABAQUS software was used to establish the three dimensional model of impact steel fiber reinforced concrete slab by the projectile,and the impact and penetration ability of steel fiber reinforced concrete is simulated.Conclusions are as follows: The impact resistance and penetration effect of steel fiber reinforced concrete is better than that of plain concrete;Increasing the thickness of the target plate and the strength of the matrix material can improve the penetration resistance of steel fiber reinforced concrete structure;The length to diameter ratio of steel fiber in concrete matrix should not be too long,otherwise it will reduce the strength of the material;When the projectile velocity is high,its penetration ability is stronger,the penetration ability decreases when the oblique penetration.