Elasto-plastic Earthquake Response Of Large-span Spatial Structure Under Wave Propagation Effect

Large-span structures are important constitute part of human modern civilization, their security is recognized excessively. Rational seismic design should allow partial member bars of the structure yield under rare earthquakes, material enters into plasticity, but the structure shouldn't collapse. Therefore the research of the elastic-plastic response of long-span structures under rare earthquakes provides reference for the structure's elastic-plastic design becomes a new subject.Based on structure's elastic-plastic theory and seismic traveling wave theory, the response of the Beijing Laoshan Cycling Gymnasium under different seismic wave velocities is analyzed by the large-scale finite element program ANSYS.Firstly, the check formula of time history analysis when structure under earthquake is deduced, material elastic-plastic and structural seismic action correlated theory are summarized. Secondly, calculation model under multidimensional earthquake is put forward; the effect of traveling wave and the influence of partial member bars collapsing and buckling are considered. The method of static equivalence is applied into Long-span structures'earthquake-resistant design, and earthquake, which is complex structural function, is translated into static loads, which provide simple and feasible method for earthquake-resistant conception design of long-span spatial structure when the effect of traveling wave is considered. Finally, elastic-plastic analysis of long-span double layer shell under different seismic wave velocities is performed, compared with the result of elastic analysis.The study indicates that the influence of seismic traveling wave on web's rim member bars is not great, but the influence on central member bars is obviously great, and the wave velocity smaller, the internal force of central member bars more great, the effect of traveling wave more conspicuous, which should be considered. By comparing the results of elastic analysis and elastic-plastic analysis, material plasticity develops internal force distribute again when the structure enters into plasticity, the internal force of yielded member bars tend to dwindle, while the internal force of unyielded member bars tend to increase, consequently the strength of structure becomes more uniform.