| The staggered truss steel frame structure system has the advantages of light weight,large internal space and less steel consumption,which is very suitable for prefabricated buildings.In order to improve the seismic performance of staggered truss structure and avoid the weak layer damage to a certain extent,the columns of staggered truss structure are replaced by energy dissipation columns which dissipate energy through energy dissipation connecting rods between columns.This structure is called energy dissipation column-staggered truss structure.In this paper,the seismic performance of energy dissipation column-staggered truss structure system are analyzed by finite.The main research contents and results are as follows:(1)The finite element model is established to verify the test results of the energy dissipation column and truss element,and the finite element analysis results are in good agreement with the test results.Then,the similarities and differences in seismic performance and failure modes of ordinary truss(without plastic design),ductile truss and energy dissipation column-truss are compared and analyzed.At the same time,a parameter analysis is carried out to study the influence of the number of vierendeel panel,the width-to-height ratio of vierendeel panel,and the height-to-width ratio of energy dissipation column on structural performance,and design suggestions are given.(2)In order to achieve the expected failure mode that the energy dissipation connecting rods in the energy dissipation column yield before the chords of truss,combining with the calculation formulas of the energy dissipation column and the ductile staggered truss structure,this paper proposes the design method of the energy dissipation column-staggered truss structure through theoretical derivation,and gives the design flow chart.A simplified calculation formula for the dumbbell-shaped energy dissipation connecting rod is proposed,which makes it more convenient to model and calculate in the design software,and to check the force condition of the structural system.(3)Based on the verification of the staggered truss structural system modeling method,two 8-story staggered truss structure models are designed,i.e.the staggered truss specimen without plastic design and the ductile staggered truss specimen.Their seismic behaviors were compared with their respective counterpart with energy dissipation columns.The static pushover analysis,modal decomposition response spectrum analysis and dynamic time history analysis are carried out by using the finite element software ABAQUS to study the seismic performance of the four specimens.The results of static pushover analysis show that the expected failure mode of the structure is achieved: under frequent earthquakes,the energy dissipation column-staggered truss structure remains elastic;under rare earthquakes,the energy dissipation connecting rods in energy dissipation columns completely yield to dissipate the seismic energy,and the members in the truss are allowed to yield to further dissipate the energy.The time history analysis under rare earthquake shows that the floor displacement distribution of ordinary staggered truss specimen under the action of each seismic wave is relatively uneven,and the weak layer is easy to appear at the bottom;the ductile staggered truss specimen is relatively evenly distributed along the floor,and there is no obvious weak layer,but the ductile staggered truss specimen shows obvious stiffness difference between adjacent floors,and the floor with more transverse trusses has larger stiffness and smaller interlayer displacement.The results show that the energy dissipation column can obviously improve the problem of concentration of interlayer deformation of staggered truss structure,and the ductility staggered truss with energy dissipation column has the best performance. |
