Study On Seismic Performance Of New Steel Structure Module Element Column Joints

Steel structure module construction is a kind of highly assembly building,the prefabricated ratio can reach 85% ～ 95%,the building process is completed module unit inside the factory,and then transport to the construction site,use lifting equipment hoisting in place,connect the key nodes,structure formed by a building as a whole,and module unit column connection nodes are the key technology of steel structure module architecture.The existing modular nodes are mostly suitable for low-rise buildings with low bearing capacity;Or the node itself is a strong beam and weak column system,can not meet the seismic requirements.Therefore,this thesis proposes a new type of steel structure module element column joint connection method suitable for Multi-story、medium and high-rise modular buildings,and studies the seismic performance of new steel structure module element column joint by using finite element simulation and dynamic time history analysis.The main contents are as follows:In this thesis,three new steel structure module element column joint specimens were designed and ABAQUS software was used to establish full scale models on the basis of the feasibility of finite element modeling,the seismic performance parameters were analyzed by the axial compression ratio,the position and number of the pad blocks between the floor beam and the roof beam,the stiffness ratio between the floor beam and the roof beam,the beam-column strength ratio,and whether or not the axillary angle,the influence of seismic properties such as hysteretic performance,skeleton curve,ductility,energy dissipation capacity and stiffness degradation under different parameters was investigated.The results show that the initial stiffness of the new joint increases with the increase of the axial compression ratio and the decrease of the beam-column strength ratio,and the ductility and energy dissipation capacity of the new joint are improved when the axial compression ratio is 0.2(within the range of 0.1 to 0.3).Setting axillary angle can improve the bearing capacity,energy dissipation capacity and ductility coefficient of the joint.The proper adjustment of the position and number of the spacers can effectively improve the joint performance of the double beam,improve the flexural bearing capacity of the joint,and the ductility coefficient of the joint can be significantly increased when the spacers are placed in the middle of the span.The flexural bearing capacity of joints can be improved by using double beams of the same section,when the stiffness ratio of bottom beam to roof beam is less than 1,the energy dissipation capacity of the joint is slightly enhanced,and some reasonable suggestions are put forward for the design of new steel structure module element column joints:new steel structure module element column joints should use the same section of module beam,set axillary Angle,placed in the span and beam end 1/4 of the spacer block,to meet the structure of strong column and weak beam.Design a six-story modular steel structure building with new node connection mode,SAP2000 finite element software is used to check the structure design,and the dynamic time history analysis is carried out,the results show that the mechanical properties of the structure meet the requirements of the code under magnitude-7frequent earthquakes and rare occurrence earthquakes.Under the action of two natural waves and one artificial wave,the base shear obtained by elastic time history analysis is not less than 65% of the base shear of the response spectrum,and the average base shear is not less than 80% of the response spectrum.The maximum interstorey drift ratio in X and Y directions appear in the second story of the structure,and the numerical value of interstorey drift ratio are within the limits of the seismic code of1/250 and 1/50 respectively,indicating the six-story modular steel structure building with good seismic performance.