The Dynamic Time History Analysis And Collapse Simulation On The Long-span Spatial Arch Turss System Under The Strong Earthquake

Because of the earthquake is sudden and destructive, it has been a major threat to human life and property. And its more and more frequently occurring makes the seismic design become the most difficult subject of the housing construction, and also to the whole civil engineering. From the world’s major earthquake disaster survey, it can be found that up to95%of the casualties were due to the damaged or collapsed of the buildings, and the incapacitate to avoid the secondary disaster that caused after the earthquake. The most direct and the most effective ways to improve the integrated defense ability of the city, reduce the disasters of earthquakes is to give an analysis about the cause of the damaged buildings which collapsed in the earthquakes and prevented it, build the architectures which can withstand strong earthquakes. In this paper, it choose the three-dimensional arch truss structure system, which are widely used in the long-span public buildings, as the object of the research, used different analysis programs to approach a subject from the structure design to the The elastic-plastic time history and failure mode analysis. The main content of the article and the results are as follows:①. The design and research of the dynamic characteristics of the model First of all, this paper use the design program of the steel structure---3D3S, according to the current Country’s specification which are relevant to the structure that were designed. Design a multitude truss arch structure which the rise to span ratio is2.5, and the truss span is60meters, and bracing structure of the truss is a steel frame with the steel columns, steel beams and the steel timbering. Then, use the famous design software---SAP2000, to get the research and analysis of the structure’s modality, which is the basis of the dynamic analysis, and according to the software’s result, the modified section was put forward to make the structure have a better property than before, to ensure that the structure have a good performance when the seismic waves come.②. The elastic-plastic seismic time history analysis of the overall structureSecondly, use the nonlinear FEM software ANSYS, which aimed is to get analysis of the whole structure, select three different kinds of the seismic waves named EL-CENTRO seismic waves, CAPE seismic waves and a synthetic seismic wave which are appropriate for the place where the structure are build. Under these seismic waves, with the software ANSYS, get the elastic-plastic dynamic analysis under the earthquake. The paper gives a description from the maximal displacement of the overall structure and the evolution of the member bar of the structure’s plastic.③.The performance comparison between the single cross mode and the whole modelBecause in today’s society, when in the evaluation of the seismic behavior of the structure like the paper shows, most of all choose to select one common of the truss as the calculation model, loading the same seismic waves, to make the comparative analysis with the whole structure model. The results indicate that under the rare happens of the earthquakes, after the structure gets into the plastic, the single cross of the structure’s performance is quite different from the whole structures. The link between each bar of the whole structure which lead to the imparity in the way of plastic flown and transmission between of the single cross of the structure. It has a huge effect on the structure’s robustness of the whole structure at the earthquake, especially the rare earthquake. Through the meticulous comparison and analysis, find that only use the whole structure to be analyzed and resolved could get the answer that are accuracy and good reliability. Also get the exactly conclusion about the performance in the rare earthquake.④.The failure process and pattern analysis of the overall structureMoreover, use the dynamic software---S-DYNA, continue working on the research of the performance of the overall structure under the rare earthquake, especially the failure process and patterns under the earthquakes, During the calculation, it is find that under the rare earthquake, the first failure bars of the whole structure is the lower chord which connected to the contact truss. Soon afterward, the connect truss of the structure get failure rapidly, and also the degree of plastic got deeper and deeper. It is very effect to delay the damage of the main truss, let the structure only had partial failure, not got the collapse of the structure. So, to the structure in this paper, the good robustness of the sub-structure of the whole model and the good made the nice performance of the structure in the earthquake. Finally, the structure didn’t collapse and without large damaged. Compared with the consequence of the software---ANS YS had gave, it almost no difference between both of the software. There is gives us the messages from another side that the result is correct.