CILAMCE 2015 Proceedings of the XXXVI Iberian Latin-American Congress on Computational Methods in Engineering Ney Augusto Dumont (Editor), ABMEC, Rio de Janeiro, RJ, Brazil, November 22-25, 2015 NONLINEAR TRANSIENT ANALYSIS OF STEEL FRAMES STRUCTURES WITH SEMI-RIGID CONNECTIONS Everton A. P. Batelo Andréa R. D. Silva Ricardo A. M. Silveira everton.batelo@gmail.com andreadiassilva@yahoo.com.br ramsilveira@yahoo.com.br Federal University of Ouro Preto - UFOP Address, Zip-Code, State, Province, Country Abstract. For all steel structural construction that involves one or more floors, the use of beam-column or even column-base connections is inherent. Due to their importance, these connections are, in steel structures, economically and structurally significant. Also in some situations, these steel buildings are subjected to a dynamic load level that can cause permanent deformation and localized damage in the structure, and this may lead to its partial or total collapse. Elastic design to avoid this behavior tends to be uneconomical. This work aims to evaluate the nonlinear behavior of steel frames structures under dynamic loads, showing the influence of the semi-rigid connections in response of the structure, and also exploring the structural hysteretic damping. Keywords: steel frames, geometric nonlinearities, semi-rigid connection, hysteretic damping