Research On Seismic Behavior Of Buckling Restrained Braced Steel Frame Structure

The buckling restrained brace is a new type of energy dissipation device.The internal core material can exhibit good hysteretic energy consumption when subjected to tensile and compressive loads,and can significantly improve the overall seismic performance of the structure.It is widely used in structural seismic design.The steel frame structure has the advantages of good toughness and light weight,but the structure is soft and the displacement will be large under the action of earthquake.Using the buckling restrained brace can not only improve the overall stiffness of the structure,but also reduce the seismic response.However,the size of the cross-section and location of the brace will affect the seismic performance of the structure,and the unreasonable design will also increase the construction cost,so it is necessary to optimize the design,so that the brace can maximize the role and cost savings.In this paper,the mechanical properties and design principles of the buckling-restrained brace are firstly summarized.The calculation formulae of the buckling restrained brace,the equivalent cross-sectional area,the equivalent stiffness and the bearing capacity are determined;and the design methods of buckling restrained brace frame structures at home and abroad are studied.As a result,an optimization design method based on the target displacement is concluded.Taking a five-story buckling restrained steel frame as an example,the required buckling-restrained brace section size for each floor is designed using this method,and ordinary support is established using YJK software.The steel frame and the buckling restrained brace steel frame model were analyzed,and the response spectrum analysis was performed.The period,floor displacement,interlayer displacement angle and base shear force of the two structures were compared.Secondly,ABAQUS software was used to analyze the time-history of the buckling restrained brace steel frame and the ordinary brace steel frame,and the seismic performance of the two structures under the multiple earthquakes and rare earthquakes was compared.Under multi-quake earthquakes,the buckling-restrained braces are in the elastic stage,and they are similar to the common braces in the structural system.The seismic response of the two structures is not much different.Under rare earthquakes,the seismic performance of the buckling-restrained brace is better than ordinary ones.The brace is to effectively reduce the seismic response through its own hysteretic energy consumption.Finally,the optimization arrangement scheme in the buckling restrained brace structure system is discussed,and the seismic performance of the buckling restrained brace steel frame structure under five different layouts is compared under the rare earthquake,and the reasonable arrangement is beneficial to reduce the seismic response.Through comparative analysis,it can provide reference for the support arrangement of similar projects in the future.