| The suspended dome structure is a late-model spatial structure composited with upper single layer reticulated shell system and lower cable-strut system, it has been widely used in long-span structures in recent years because of its good performance with external loads as well as its new and beautiful structural style. Now, most researches have focused on its static characteristics, very few have tested its different regions’ imperfection sensitivity or its other dynamic characteristics. This paper will use Houjie Gymnasium as the research project, computes and analyzes suspended dome structure’s static and dynamic characteristics. The main contents are summarized as follows:(1) This paper proves the feasibility of the improved stochastic imperfection method on the suspended dome structure’s static stability analysis, and also completes the overall suspended dome structure’s and its corresponding single layer reticulated shell’s imperfection sensitive region analysis. In addition, the influences of different live load distributions and the change of the topological form are further discussed. The research shows the following three conclusions. Firstly, the imperfection sensitive region of suspended dome structure has great difference with that of its corresponding single layer reticulated shell, the influential region and sensitive degree are both less than those of single layer reticulated shell because of the introduction of cable-strut system. Secondly, the half-equitant distribution of live loads has no significant influence on the suspended dome structure’s imperfection sensitive region. Lastly, the change of traditional topological form improves the related region’s imperfection sensitivity.(2) This paper compares the effects of different seismic wave simulation modes and initial geometric imperfection modes on the structural dynamic response,and also studies the reasonable maximum values of imperfection. The research shows the following three conclusions. Firstly, compared with global consistent method, the structural dynamic response results obtained by support large mass method are more conservative, so, in the engineering practices, the support large mass method seems to be a better method to calculate structural dynamic response. Secondly, when using stochastic imperfection modal method as a baseline reference, the consistent imperfection mode method to some degree overestimates the structural dynamic responses, and natural imperfection mode method also seems not to be reliable if the peak acceleration of seismic wave is less than 400cm/s2. Lastly, it is more suitable for the suspended dome structure of Houjie Gymnasium to take L/500 as the reasonable maximum value of imperfection instead of L/300.(3) This paper uses the maximum node displacement and characteristic node’s displacement and time curve as the two main indexes to verify the stage of structural dynamic stability, and also takes strain energy, displacement ductility factor, yield factor and other related parameters into consideration, so, as a result, it reveals the change of structural performance from both the macro level and the micro level. The research shows the following three conclusions. Firstly, the structural dynamic critical load obtained by the support large mass method is far more less than that obtained by the global consistent method, this difference is mainly due to the prestressed cable’s wresting and extending dynamic properties under the seism action. Secondly, when using the global consistent method and taking the initial geometric imperfections into consideration, the change of the dynamic instability critical load of the imperfection structure is less than 10% compared with that of the perfection structure, the influence is little. Lastly, when using the support large mass method, the dynamic instability critical load of the imperfection structure is decreased by 20% compare with that of the perfection structure, the influence is obvious. |
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