Dynamic property and seismic performance of square-based membranous latticed shells

Abstract

The basic natural vibration property of the square-based single layer membranous latticed shell is analyzed using the subspace iteration method. Then, the seismic performances of the structure are studied in detail by the mode-superposition response spectrum method, and the reasonable combination number of vibration modes in seismic analysis by the mode-superposition response spectrum method is investigated. In addition, the formulas of seismic time-history response of a long-span spatial structure are deduced considering geometrical non-linearity, and the corresponding computer program is developed. The results by the response spectrum method and those by the time-history method are, then, compared. The researches show that, the seismic performance of the square-based membranous latticed shell is comparatively well, and the reasonable combination number of vibration modes is 15 in the vertical seismic analysis of this kind of structure by the mode-superposition response spectrum method, whereas, it is 60 in the horizontal seismic analysis. Moreover, the results of the vertical seismic analysis of the structure by the mode-superposition response spectrum method are on the safe side, whereas, in the horizontal seismic analysis of the structure, the results must be checked by the time-history method at the end. All this work will provide theoretical guidance to the actual engineering application of this structure.