Approximation Frequency of Dominant Modes in Double Layer Grids by Using Fuzzy Logic and Genetic Programming

فاقد چكيده فارسي

Dynamic analysis of space structures is very complex and time consuming due to high degrees of freedom and the large number of elements. In conventional buildings, the dominant modes appear in the first modes of vibration, while in space structures they may be appeared in the higher modes so, in these types of structures the dominant modes cannot be achieved easily. In this article the frequency of dominant modes of double layer grids is approximated based on the percentage mass participation by means of Fuzzy Logic and Genetic Programming. For this purpose, the frequency variation of dominant modes in double layer grids induced by the effects of changes in the ratios of height to span length and variations of gravity loads has been studied. In continue, the frequency of dominant modes is estimated by means of fuzzy logic and genetic programming. Finally results of both systems have been compared.