Study On Seismic Performance Of GFRP Beam-Column Joints With Slotted Holes

Glass fiber reinforced composite(GFRP)is a new type of material used in construction in recent years,which has the advantages of light weight,high strength and corrosion resistance.However,the application of GFRP in building structures requires reliable joints,so the study of seismic performance of GFRP beam-column joints is of great significance to the application of GFRP materials in building structures.Based on the research results of GFRP beam-column joints at home and abroad,this paper analyzes the seismic performance of reamed GFRP beam-column joints by combining experimental analysis with ABAQUS finite element numerical simulation analysis.The main research contents are as follows:1.The GFRP beam-column joints(N1,N2,N3)connected with casing were tested under cyclic loading,and the influences of reaming,preloading force and side plates on their seismic performance were studied.The bending moment-rotation hysteretic curve,ultimate bending moment and load-stress curve of the joints were obtained.The experimental results show that :(1)the energy consumption of the reaming joint is about 18% higher than that of the non-reaming joint.(2)The failure mode of the joint without side plates is that the GFRP column is crushed by the end plates,while the failure mode of the joint with side plates is that the upper flange of the beam is torn.(3)The greater the preloading force,the greater the friction,and the less obvious the pinching of the hysteretic loop curve.2.The GFRP beam-column joints(D1,D2)connected with Angle steel were tested under cyclic loading,and the influences of reaming and preloading force on their seismic performance were studied.The bending moment-rotation hysteresis curve,ultimate bending moment and load-stress curve of the joints were obtained.The experimental results show that :(1)the energy consumption of the reaming joint is about 18%higher than that of the non-reaming joint.(2)The failure mode of the joint without side plates is that the GFRP column is crushed by the end plates,while the failure mode of the joint with side plates is that the upper flange of the beam is torn.(3)The greater the preloading force,the greater the friction,and the less obvious the pinching of the hysteretic loop curve3.The seismic performance of GFRP beam-column joints connected by two groups of Angle steel was studied by ABAQUS finite element numerical simulation method.One group is the nodes with different reaming lengths(D3,D4),and the other group is the nodes with different preloading forces(D2-U1,D2-U2).The following conclusions are obtained :(1)The longer the reaming length is,the longer the slip section is.When the reaming length increases by 2mm,the slip Angle increases by 0.01rad-0.2rad.(2)The larger the preloading force is,the greater the slip load is.When the preloading force increases by 5k N,the slip load increases by 0.3k N-0.4k N.(3)When the reaming length remains unchanged,increasing the preloading force of the high-strength friction type bolt can effectively increase the ductility,especially when the preloading force increases from 5k N to 10 k N,the ductility increases by about one time.(4)The ductility can increase between 7%-41% for each2 mm increase in the reaming length,especially when the reaming length increases from 4mm to 6mm,the ductility increases by 41%.