Large Span Steel Truss Roof Dynamic Performance And The Seismic Response Analysis

With the rapid development of society and the progress of science and technology, people more and more high to the requirement of the modeling of building and using.Since the new century, large span truss structures in the construction industry has become the hot topic in the study of people that can meet people’s new demand.Because the large space, beautiful shape and convenient construction, domestic and foreign research scholars began to focus on research of large-span steel structure stress performance, and considering the seismic performance of the structure.Large span steel structure of the domestic research conclusion has its limitation, it need further perfect.This topic use the large-scale finite element analysis software SAP2000to simulate the steel truss roof structure of Suzhou railway station,through the analysis of the static and dynamic performance of the model, summarizes the static performance of the structure and seismic response analysis, for large span structure in the future provide some useful help and reference to engineering design and analysis.The main research content is as follows:Firstly,the roof under the combination of five load condition,static analysis was carried out on the roof structure by using the finite element software SAP2000, so that can receive the reaction force and the corresponding dangerous bearing and adverse condition combination.In the X axis and Y axis of this structure choose some chord members and web members, through the changing of these axial forces,to understand the change of the axial force on the roof.Steel bars are connected by nozzle-vessel junction nodes,under the five working load combination,analyzing the vertical displacement of upper chord and bottom chord nodes and the effect to the joint from the five kinds of combination of nodes.Secondly,in SAP2000environment,the steel truss roof structure conduct modal analysis,and get the cycle and frequency of the structure before50order vibration mode.Through the data integration and analysis can be obtained that the frequency are close and complex vibration.It will need more modal data to combine in order to get more accurate result. Thirdly,use the response spectrum method in half span of roof structure, to analysis and compare the vertical dynamic displacement under horizontal and vertical earthquake in the upper and lower nodes of the long span and short span in the roof.so that can get the displacement data of eath node and the position of the biggest gap between the nodes upper and lower.The conclusion is the effect to the performance of the structure from the horizontal and vertical earthquake.The fourth,By using the time history analysis and response spectrum,compare the displacement of the nodes and substrate reaction force,it satisfies the standard.In the end,to summarize the research work and achievement mentioned above,then point out some conclusions valued in this study and some questions need to be solved in the future.