The Study Of Impact Resistance On RC Floor Slabs Reinforced With FRP Materials

Carbon fiber reinforced polymer（CFRP）has been widely used in the reinforcement of industrial,civil and military building structures due to its advantages of light weight,high strength and easy construction.However,the dynamic response of CFRP reinforced RC structures under impact load is less studied.In this paper,the impact resistance of RC floor reinforced with CFRP under the impact of elastic body is numerically simulated,which has important engineering significance for structural reinforcement and repair.The main research contents are as follows:（1）RC structures exhibit different mechanical properties under dynamic load and static load.In this paper,the mechanical properties of RC structures under dynamic load and the material constitutive model based on strain rate effect are studied.（2）Carry out numerical simulation on the existing test of projectile impacting RC plate to verify the accuracy of the model.The results of RC plate deflection,projectile residual velocity and concrete damage obtained in numerical simulation were compared with the experimental results.It was found that the selected constitutive model and parameters could well restore the failure process of CFRP-RC plate,which verified the accuracy of the material model and parameter setting.（3）The impact of CFRP reinforcement on the impact resistance of RC slabs in typical building was studied.The parameters include impact velocity,relative position of steel bar and projectile body,Angle and number of CFRP layers.The results show that when the impact velocity changes,the residual velocity of projectile,the system energy and the damaged area of RC floor are most affected by the impact velocity.When the relative position of projectile body and steel bar changes,CFRP reinforcement has the greatest influence on the impact resistance of RC floor slab when it hits the intersection of steel bar.When the Angle changes,the damage of RC floor is the largest when the Angle of projectile body is 60°,and the damage area can be reduced by 11% ～ 33% when the first ～ third floors are reinforced with CFRP.When the Angle is 0° and there is no direct action with the reinforcement,the projectile body can penetrate the RC floor most easily.The maximum penetration depth of the projectile body is 67 mm,and the ballistic ultimate velocity can be increased by 9.4% under the two-layer CFRP reinforcement.