Study And Ana Lysis On Overall Stability Of A Large Span Arch Steel Beam Structure

In recent years,with the enhancement of China’s economic strength and the needs of social development,long-span steel structures have been widely applied and developed rapidly.The most significant characteristics of the large span steel structure are the overall stability characteristics,especially the application of the high strength materials.The analysis model and technology are becoming more and more meticulous.The weight of the large span steel structure is lighter,the span is larger,the stiffness is more soft and the body is more complex,and so on.This determines that the analysis of the overall stability of a large span steel structure needs to consider the nonlinearity.It is necessary to consider the initial defects of the structure effectively,and the dual nonlinearity of the coupling between the geometric nonlinearity and the material nonlinearity should be considered when necessary.The current "steel structure design code" mainly solves the stability of the component and the single plate,ensures the stability of the single member by the stability of the single plate,and ensures the stability of the whole structure by using the single component.This method of stability is not applicable to the overall stability analysis of long-span steel structures,which brings theoretical bottlenecks to engineering designers.Therefore,this paper mainly uses MIDAS/Gen and SAP2000 to analyze the overall stability of the large span steel structure of the China Pharmaceutical Exhibition Center.Through the analysis,it provides valuable reference for the similar large span steel structure after the analysis,which is the same as the following.The model of the project is established by 3D3S and MIDAS/Gen,then the period and formation are compared,the accuracy of the model is determined,and then the eigenvalue buckling analysis of the model is carried out by MIDAS/Gen.The results show that the eigenvalue buckling analysis is not consistent with the real situation.Then the MIDAS/Gen model is used to consider the nonlinear analysis of the initial defects.The results show that with the decrease of the defects,the stability bearing capacity coefficient of all kinds of load combination increases gradually.Finally,the effect of different boundary constraints on the elastic stability of large span steel structures is considered.The results show that the column and the foundation are more beneficial to the large span steel structure with the hinge constraint from the angle of sensitivity.Using MIDAS/Gen and SAP2000 to consider the result of nonlinear calculation of the structure and considering the double nonlinear calculation results of geometry and material,it is known that the ultimate bearing capacity of the structure is obviously reduced after considering the double nonlinearity.Therefore,for this large span steel structure,it is necessary to consider the geometry and the geometry of the structural stability bearing capacity.The effect of material double nonlinearity.Then,by changing the boundary constraint conditions,it is found that the boundary constraints still have some influence on the elastoplastic ultimate bearing capacity of the structure by using the SAP2000 software.The boundary constraint conditions chosen for this project are more suitable and economical.The time history analysis method is used to analyze the seismic response of the long-span steel structure under the seismic excitation of the fortification intensity,check whether the structure meets the seismic design requirements,and judge the seismic performance.Two groups of actual seismic waves and one group of artificial waves are used to calculate the horizontal seismic action in the two principal axes of the structure,and the calculated seismic response value of the structural node displacement fully meets the specification and design requirements.