Stochastic Dynamic Analysis of a Tower Excited by Wind Forces
Reyolando Brasil1; Gustavo Pedroso1; José Balthazar2; Angelo Tousset3; Vinicius Piccirillo3; Jorge Felix Palacios4
1 Universidade Federal do ABC; 2 ITA; 3 Universidade Técnológica Federal do Paraná; 4 Universidade Federal do Pampa
doi:10.20906/CPS/USM-2016-0054
Resumo
We present a time domain analysis of a tall variable section metallic tower under wind action. An equivalent one-degree-of-freedom model is generated via the classical Rayleigh's Method. A Monte Carlo type of procedure, called the Synthetic Wind, due to Prof. Mario Franco, is used to simulate dynamic wind loadings, of random nature. We apply a superposition of several harmonic loads with randomly set phase angles and amplitudes corresponding to spectral density function (PSD) selected frequency bands. The used PSD function is the one proposed in the Canadian Wind Forces on Structures National Code by Prof. Davenport. Computer processing results in a very large series of displacements and structural stresses time histories. With these numerous response time histories, mean and standard deviation of peak values are computed and a probability density function, the Gumbel distribution, is adopted. Thus, it is possible to make reliable engineering assessment of structural reliability and life expectation.
Palavras-chave: stochastic dynamics; random vibrations; wind forces on structures; fluid structures interation