Research On The New Type Of Double Round Steel Buckling-restrained Brace With End Reinforcement

Buckling restrained brace,as a kind of energy dissipation and shock absorption member,has been widely used for its advantages of yielding without buckling,full hysteretic curve and stable energy dissipation performance.The traditional buckling restrained braces usually adopt the structural form of the restraint element outside and the core force element inside,but it is difficult to check the damage degree quickly and conveniently after the earthquake,and the secondary damage may occur during the inspection process.In order to solve this problem,this research adopts the structural form of the core force element outside and the constraint element inside.Using ABAQUS to analyze the new type of double circular steel tube bucklingrestrained brace with end reinforcement.In the analysis,one-way tensile load and low cycle reciprocating load are applied to the new type of buckling-restrained brace,and the effects of slenderness ratio,diameter thickness ratio,restraint ratio,clearance between the core stress element and the restraint element,friction coefficient and initial defects on the mechanical properties of the support are studied;the seismic response of the buckling-restrained brace and the common support frame are studied,respectively,on the dissipation energy,interlayer displacement and support Through the comparative analysis of deformation,storey displacement and acceleration,it is verified that the new type of double circular steel tube end strengthened buckling-restrained brace is effective in improving the seismic performance of the structure.The ABAQUS finite element software is used to simulate the new type of double circular steel tube with end reinforcement.The results show that the new type of double circular steel tube with end reinforcement has good mechanical properties;the smaller the gap between the restraint element and the core stress element is,the more favorable the brace is,the 2mm is generally appropriate;in the design,the initial defects should be avoided as much as possible The larger the restraint ratio is,the more favorable the mechanical performance of the brace is,the fuller the hysteretic curve of the brace is;the smaller the slenderness ratio is,the greater the bearing capacity of the brace is,and the larger the slenderness ratio is;the more likely the brace is to buckle locally.so the range of the ratio of diameter to thickness under different slenderness ratio is summarized.The ratio of diameter to thickness has little effect on the overall buckling of the brace.In the study of the frame structure,it is found that under the frequent earthquake,the three kinds of frames are in the elastic state.The amplitude of storey displacement,support deformation,storey shear force and acceleration of the buckling resistant braced frame is the same as that of the common braced frame,while the dissipation seismic energy of the buckling resistant braced frame is less than that of the common braced frame.Under the rare earthquake,the storey shear force of the buckling resistant braced frame is greater than that of the common braced frame Support,in addition,are smaller than ordinary support.Therefore,the mechanical properties of the new type double circular steel tube buckling-restrained brace with end reinforcement are better than that of the ordinary brace,which can improve the seismic performance of the structure more effectively.