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چکیده
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In this study, a new approach is proposed for seismic design of latticed dome structures using natural frequencies. In order to obtain the critical natural frequencies, the structural behavior of two types of latticed domes, including a shallow double-layer dome and a single-layer Diamatic dome, under earthquake excitation is investigated. For this purpose, response history analysis is utilized considering the multi-component excitations. Also, the effects of two different mass definitions for the structure are studied. After conducting a suitable structural design based on nodal displacement and member stress criteria, the frequency content of each accelerogram obtained by Fourier amplitude spectrum is compared to range of the first ten natural frequencies of the designed structure. Results indicate the distribution of natural frequencies with respect to the frequency contents of earthquake accelerograms, and thereby revealing a critical frequency range for which a structure should be designed in such a way that its natural frequencies do not belong to that critical frequency range. This critical frequency range is appropriately far from the dominant frequency range of the selected earthquake accelerograms. The proposed approach can be applied for design of dome structures under earthquake excitations, which uses the natural frequency constraints (instead of displacement and stress constraints) to estimate a suitable design within less computational time.
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