Seismic Performance Analysis Of Irregular Concrete Frame Structure With Buckling Constrained Bracing

As a new type of energy-consuming support,the buckling restraint support(BRB)has the advantages of light weight,easy installation and flexible layout.The application of buckling-constrained bracing to a building structure not only improves the lateral stiffness of the structure,but also dissipates seismic energy before the main structure yields,reducing the seismic effect on the main structure.Irregular concrete frame structures are prone to torsional damage under earthquake action.In view of the mechanical characteristics of this structure,buckling restraint supports are arranged at appropriate locations of the structure to increase the structural lateral rigidity while reducing the torsional effect of the structure.In this paper,the finite element simulation of the buckling constrained brace is carried out to study its energy dissipation performance and analyze its influence on the seismic performance of the irregular concrete frame structure.The main research contents and results are as follows:1.Establish different types of buckling constrained supports through numerical simulation.By adjusting the cross-sectional area and width-to-thickness ratio of the supporting core material,changing the relevant parameters of the rigidity of the peripheral constraining element,the gap between the core material and the peripheral constraining element,etc.to analyze various variable pairs Buckling constrains the impact of support performance.2.In view of the stress characteristics of irregular concrete frame structures that are prone to torsional failure under earthquake action,this article takes an L-shaped frame structure office building project in Xi’an,Shaanxi Province as an example,and applies the finite element analysis software Midas/Gen to the original frames respectively.The structure and the buckling constrained support were added to analyze the seismic performance of the structure.(1)By changing the layout and location of the braces,the variation laws of the interlayer displacement angle,torsional displacement ratio and period ratio of the buckling-constrained braced-frame structure under frequent earthquakes are analyzed.Studies have shown that the chevron-shaped support arrangement has obvious advantages over the zigzag shape.Arrangement of the support at the peripheral position of the structure can significantly reduce the torsional effect of the structure.Following the chevron layout,based on the design method of lateral stiffness ratio,five buckling-constrained brace-frame structures with different stiffness ratios of 0.5,1.0,1.5,2.0,and 2.5 were selected,and the interlayer displacement angle and torsion were compared and analyzed.Displacement ratio and period ratio in order to obtain a reasonable stiffness ratio suitable for this project.Studies have shown that the reasonable lateral stiffness ratio of buckling-constrained braced-frame structures ranges from 0.5 to 2.0.(2)The original frame structure and the buckling constrained brace-frame structure were analyzed and calculated under the rare earthquakes,and the interlayer displacement angle and hysteresis curve were compared.The results show that the buckling constrained brace-frame structure has superior seismic performance performance.