ResearchArticle Energy Dissipation and Local, Story, and Global Ductility Reduction Factors in Steel Frames under Vibrations Produced by Earthquakes Alfredo Reyes-Salazar , 1 Ed´ en Boj ´ orquez , 1 Juan Bojorquez, 1 Federico Valenzuela-Beltran , 2 and Mario D. Llanes-Tizoc 1 1 Facultad de Ingenier´ ıa, Universidad Aut´ onomadeSinaloa,Culiac´ an, CP 80040 Sinaloa, Mexico 2 Instituto de Ingenier´ ıa, Universidad Nacional Aut´ onomadeM´ exico,CP04510CiudaddeM´ exico, Mexico Correspondence should be addressed to Alfredo Reyes-Salazar; reyes@uas.edu.mx Received 5 June 2018; Accepted 17 September 2018; Published 14 October 2018 Academic Editor: Giorgio Dalpiaz Copyright © 2018 Alfredo Reyes-Salazar et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Ductility plays a central role in seismic analysis and design of steel buildings. A numerical investigation regarding the evaluation of energy dissipation, ductility, and ductility reduction factors for local, story, and global structural levels is conducted. Some steel buildings and strong motions, which were part of the SAC Steel Project, are used. Bending local ductility capacity (µ Lϕ ) of beams can reach values of up to 20, as shown in experimental investigations. e values are larger for medium than for low-rise buildings, reflecting the effect of the structural complexity on µ Lϕ . Most of the dissipated energy occurs on beams; however, resultant stresses at columns are also significantly reduced by beam yielding. A value of 1/3 is proposed for the ratio of global to local ductility; thus, if local ductility capacity is stated as the basis for the design, global ductility capacity can be calculated by using this ratio. It is implicitly assumed in seismic codes that the magnitude of the global ductility reduction factor is about 4; according to the results found in this paper, it is not justified; a value of 3 is observed to be more reasonable. According to the well-known ratio of the ductility reduction factor to ductility, this ratio should be unity for the models under consideration; the results of this study indicate that, for global response parameters, a value of 3/4 is more appropriate and that, for local response parameters, values larger than 2 can be reached; the implication of this is that using simplified methods like the static equivalent lateral force may result in nonconservative designs from aglobalstructuralpointofview,butinconservativedesignsfromalocalpointofview.Avalueof8isproposedfortheratioof the global ductility reduction factor to the global normalized energy. 1. Introduction Even though building structures undergo significant nonlinear deformations when subjected to strong earth- quakes, simple elastic procedures are still used to determine the seismic demands (International Building Code (IBC) [1], National Building Code of Canada (NBCC) [2], Mexico Federal District Code (MFDC) [3], and Eurocode 8 (EC) [4]). Simplified methods like the Static Equivalent Lateral Force (SELF) are broadly used for regular buildings with relatively short periods (low- and medium-rise). However, while using this procedure in steel buildings, it is not possible to properly capture the effects of nonlinearity introduced by large deformations, by the connections, and by nonlinear geometry. In addition, dissipation of energy due to yielding of the material is considered in a very crude way. According to the method, static analysis of the buildings subjected to equivalent lateral forces, which are related to the properties of the structure and the seismicity of the region, provides the design forces. In the procedure, the ductility parameter (µ) plays an important role in the determination of the design seismic forces since it is as- sociated with the energy dissipation structural capacity produced by nonlinear behavior, allowing for a reduction Hindawi Shock and Vibration Volume 2018, Article ID 9713685, 19 pages https://doi.org/10.1155/2018/9713685