Mechanical Properties Of Damaged Steel Beam Strengthened With CFRP Reinforcement

Because of its high strength,uniform texture,stable quality,good plasticity and toughness,construction simple and easy maintenance and a series of advantages,Steel structure is more and more applied to various fields.In recent years,fiber reinforced polymer(FRP)with its advantages of high strength,light weight,corrosion resistance,began to get application in civil and building engineering structure,and received extensive attention of engineering.Steel element after a certain time of service will produce different degrees of injury,the existing fixed value of damaged members,after reasonable reinforce and repair technology can make its continue to load and ex tend its service life.This article mainly aims at common injury-crack in the steel beam as the research object,analyzing the mechanical properties of steel beams with different crack damage after CFRP reinforced.This article first summarizes the existing theory achievement,analyzing the adhesive interface between CFRP and steel beam through the existing theoretical model.Analyzes the factors of affecting its mechanical performance and the possibility of failure mode.Comparative analysis of the fin ite element model,select the appropriate finite element model.The model’s reliability is proved by the existing experimental data,and applied to the parameter analysis.Through the finite element modeling of damageded steel beam with different amount of reinforcement,crack length and crack width,the simulation results show that: after CFRP reinforced the damaged beam,bearing capacity and stiffness are greatly improved.With the increase of reinforcement layer at the same time of constantly improve the bearing capacity,the failure mode changes from brittle failure for plastic damage,more conducive to structure safety.The length of the cracks on the cross section is the important factors influencing the bearing capacity of the reinforced,for the influence of the stiffness is relatively small.Crack width have less effect on the mechanical properties,the change of bearing capacity and stiffness after reinforcement are not obvious.