On Static And Dynamic Capability For Combined Structures Of Lattice Shells And Concrete Column Supports

In recent years, combined structures of double-layer spherical lattice shells and concrete columns supports have been wildly applied in such buildings as gymnasium and so on. However, systemic research on the static and dynamic characteristics of such structures has been seldom carried on. A systemic research on the static and dynamic characteristics of such structures is carried out by the author, and two key problems as boundary circumstances and the global damping radio of such structures are analyzed in this paper for reference for the calculation and analysis in practical project.Firstly, the static characteristics of such structures of different parameters are calculated used by finite element methods. The distribution of static force and the influence of structure parameters to the static characteristics are analyzed. The differences between the overall model and simplified hinge support model are also analyzed, and the result shows that the differences are great. In general, the force of main members in hinge support model is largely decreased in comparison to the overall model and it may give unsafe design inner forces. Therefore, the overall model must be adopted to calculate such structures.Secondly, free vibration characteristics of such structures are analyzed by Rayleigh-Ritz method and the influence of structure parameters are also analyzed.Thirdly, earthquake responses in various direction of column-supported lattice shell structure are analyzed in comparison by different methods, including the applied method based on plural damping theory, author's self-compiled dynamic procedure'DAST'based on Clough's sub-structure theory, adopting the damping ratio of steel as whole, the distribution of dynamic force in various directions is pointed out. In addition, the differences between the whole and simplified hinge support model are also analyzed, and the result shows that the differences are large. The force of main members in hinge support model is twice more than the according one in overall model. In general, adopting hinge support mode is conservative to calculate the earthquake responses.Finally, some design proposals for static and dynamic calculation of column-supported lattice shells are put forward.