Study On Dynamic Response Of CFRP-Reinforced Square RC Members Under Unequal Transverse Impact

The building structure regularly needs reinforcement due to damage,specification requirements,functional changes,and so on;carbon fiber polymer(CFRP)is widely used in structural reinforcement due to its high strength,lightweight,good corrosion resistance and easy construction.The regular square section reinforced concrete frame members strengthened by CFRP material is taken as the research object.The dynamic response of CFRP to reinforced concrete members under unequal cross-impact is discussed.The main research contents and results are as follows:(1)The experimental research demonstrates that the test components are subject to the bending failure mode,the impact point and the near impact point support are severely damaged areas;the transversely wrapped members are more abruptly broken,and the longitudinal wrapping members and the number of wrapping layers can effectively reduce the level of damage.(2)Analysis of the impact time history curve,deflection time history curve and strain time history curve obtained in the test shows that the wrapping mode and the number of layers have less influence on the impact force peak;the longitudinally wrapped components and the platform segment take longer.The horizontal partition platform segment fluctuates greatly;the increase in the number of vertical wrap layers increases the platform value.The larger the number of layers,the smaller the deflection caused by the impact,and the longitudinal wrapping can effectively transmit the force.(3)Based on the test and the current test outcomes,the short-term bending stiffness Bs is proposed to characterize the anti-collision capability of CFRP-reinforced RC concrete columns.Based on the derivation of others,the expression of CFRP-reinforced RC structural member Bs is proposed.The theoretical calculation results are compared with the existing experimental results,and the applicability of the formula is verified.(4)The finite element model is established,and the finite element analysis results were compared with the experimental results to verify the correctness of the finite element model.Based on the finite element analysis,the effects of impact velocity,concrete strength,longitudinal steel reinforcement ratio and CFRP layer on the impact resistance of the members were analyzed.The optimal value of CFRP reinforcement layer was proposed.