| The development of spatial structure is one of the significant symbol to measure a country’s construction science and technology. With the rapid development of social economy and the progress of human science and technology,A lot of large span steel roof structure that has neoteric architecture form and unique type has been widely used in various construction projects, especially in large public construction projects. The project has been all over the country.The theories and experiment about large span spatial structure has been increasingly mature, but for The overall performance and damping theory under the action of the earthquake is not perfect. Once the structures be destroyed or collapse under the effect of sudden earthquake, the consequence is very serious, especially many large-span space structures are located in the strong earthquake zones in our country,including that in building and existing. Therefore the related research still needs to be further carried out.At present, the anti-seismic research about plate type truss structure and reticulated shell is more,but the research on the dynamic properties of large-span spatial steel truss structure is less. The current anti-seismic measures in spatial structure mainly include three kinds of methods:the traditional anti-seismic design, isolating vibration design, energy dissipation and vibration control design.Buckling restrained brace is a remarkable kind of vibration control device with advantages of being economical under minor earthquakes,having no failure under middle earthquakes,being repairable under major earthquakes. It can be installed in large-span spatial structures to control the vibration structures as a novel device of high performance.This paper using software ANSYS for simulation, taking a Large-span steel truss structure as the research object which has independent columns as supporting structure, analyzed static and dynamic interaction about steel truss roof structure and the supporting system working together, draw the conclusion when analysis of the steel truss roof must consider the combination of the lower supporting structure. In addition carried out the anti-seismic research about application of BRB in a whole structure, through different BRB layout mode in upper truss or lower supporting structure and the different time-history input,the reasonable bracing layout was obtained.In optimal layout,internal force of bars can be decreased by more than30%.In the end, based on a actual project which is large-span space steel truss structure, studied the application of BRBs in the whole structure and its damping effect when the steel truss roof and supporting structure working together by nonlinear time history analysis method. Through analysis of different BRBs layout mode, It turned out that the damping effect can be effected by BRB arrangement directly.The damping effect is limited after setting BRBs on upper steel truss only. And when they are setting in the lower supporting structure, the displacement and internal force of the upper steel truss rods can be reduced effectively.So, considering damping effect and economic factors,setting BRBs in the lower supporting structure reasonably has a good damping effect. |
