The Seismic Performance Analysis Of Long-span Space Tube Truss Roof Structure In Nanyang South High-speed Railway Station

Large span space structure because of its own characteristics,the structure with small amount of steel,overall stiffness,beautiful architectural effect,strong artistic expression,in the design can be combined with the most cutting-edge,the most advanced steel structure design concept,as a new space structure system,has been widely used.However,most of these structures are densely populated after they are put into use,and some of them have a certain international influence,so it is of great significance to study their seismic performance.In this paper,the large-span space tube truss roof structure of nanyang South High-speed railway station house is taken as the research object,and the seismic performance of the structure is analyzed by using Midas Gen finite element analysis software.The main research work is as follows :(1)Using the finite element software Midas Gen,the finite element model of the roof structure is established,and the static analysis of the structure is carried out.Based on the deformation,stress ratio distribution and the bearing capacity analysis of key nodes under the design load,the static performance of the structure is understood.The analysis results show that the flexural span ratio of the structure meets the requirements of the code,the stress of the rod is small,the structure design is reasonable,and the safety factor of the rod is high.(2)Modal analysis,response spectrum analysis and dynamic time history analysis were carried out for the structure under the action of multiple earthquakes.Based on the displacement response and dynamic internal force response law of the structure under the combined action of earthquakes in different directions,the natural vibration characteristics and seismic performance of the structure were obtained.The analysis results show that the lateral stiffness of the structure is evenly distributed along the main direction,the x-direction stiffness of the V-pillar region is large,and the y-direction stiffness is weak in the middle and strong at both ends.The distribution laws of dynamic internal forces of rods are different greatly,and the horizontal seismic action has obvious influence on v-shaped support columns.(3)The elastic-plastic analysis model of the roof structure was established by Midas Gen,and the nonlinear elastic-plastic time history analysis of the structure was carried out.Based on the development state of plastic hinges,the ductility coefficient(D/D1)distribution and the ratio of energy dissipation,the seismic performance of the structure under the action of rare earthquakes was analyzed.The plastic failure mechanism of structurally weak member is studied by increasing the peak acceleration of seismic wave and making the member enter the yielding state.The analysis results show that the seismic performance of the whole structure is good and can achieve the predetermined seismic fortification target.The weak positions of the structure are mainly concentrated in the inner side of the V-pillar,and gradually develop upward from the bottom,which is easy to be destroyed first under the action of strong earthquakes.