Seismic Performance Analysis Of Column-to-column Combined Modular Steel Frame Buildings

In recent years,under the background of manufacturing industry transformation and upgrading,the country had vigorously promoted prefabricated structure.Modular steel building is a kind of prefabricated steel structure with high degree of assembly,which has the advantages of fast construction speed,no weather influence,saving labor and improving the quality of building structure,etc.Modular steel structure building system have some structural characteristics such as"eight columns with sixteen beams","four columns with eight beams"and"two columns with four beams"at the beam-column connections.The mature connection ensure the safety and reliability of beam-column connections.However,because of the lack of connection between the module columns,they still bear the load alone,and the integrity of the component is not strong.At present,there were few researches on the module columns and seismic performance of modular steel building in our country.Under this background,this paper proposes a kind of column-to-column combination tied with steel plate.The design idea is to weld the rectangular steel plate at the adjacent columns of the module unit.The"four columns"and"two columns"were connected with each other,forming a strong column-to-column combination,working together and enhancing the bearing capacity.At the same time,when the component is subjected to horizontal force,the displacement between the modular columns is staggered.The outer steel plate b etween the columns is sheared,which enter into yield to play the role of energy dissipation,enhancing the energy dissipation capacity of the component.Based on an example of a 10-story modular steel frame structure,making a reasonable assumption about the connection of the module unit.Creating an integral model calculation to obtain the mechanical index which meet the requirements of the code.Focusing on the failure mode of column-to-column combination in modular steel building.After theoretical calculation and finite element buckling analysis,the results show that the column-to-column combination is strength yield failure when the slenderness ratio is small,and the whole instability failure occurs when the slenderness ratio is large.Considering initial defects,the axial post-buckling analysis of column-to-column combinations with different inter-column gapΔ_G is calculated.The result shows that the ultimate load of axial compression increases first and then decreases with the increase ofΔ_G,and the maximum axial load and optimum gap exist.A kind of column-to-column combination tied with steel plate was designed to study the effect of load capacity and energy dissipation capacity.The axial displacement loading results show that the ultimate axial compression load of the column tied with steel plate is greatly improved.The horizontal displacement loading shows that the initial stiffness and yield load can be increased by changing the size parameters and material properties of the steel plate.The cyclic loading results show that the hysteretic curve is full,the energy dissipation coefficient is improved,and the seismic performance is good.Finally,a frame is extracted from a 10-story modular steel frame structure.Three seismic wave records are inputted,and dynamic time-history analysis under frequent and rare earthquakes is carried out,respectively.The corresponding mechanical performance indexes,including vertex displacement,inter-story displacement angle,base shear force,are compared with a frame without steel plate.The analysis results show that the column-to-column combination tied with steel plate has a good vibration absorption effect in the whole structure.