Non-linear behavior in building frame structures is inevitable and expected in moderate to
severe seismic events. This behavior tends to be concentrated at the ends of beams and columns of
moment-resisting frames. These critical regions, where plastic hinges form, are important for the
global stability of the structural system. Depending on the available ductility, these mechanisms are
responsible for the permanent deformations that the structure undergoes, leaving the remaining parts
of the structural elements in the elastic regime, and hence in the safe zone. The importance of these
mechanisms led to the search for an adequate model capable of well-capturing the non-linearity
phenomena involved. The development of versatile hysteresis models with degradation features has
been the aim of different studies. Hence, this paper presents a parametric study based on a smooth
hysteresis model, a further modification to the well-known Bouc-Wen model, developed by
Sivaselvan and Reinhorn, with a physical interpretation appropriate to the study of the non-linear
behavior of civil engineering structures, particularly, building structures. Furthermore, an
optimization procedure is implemented to calibrate the mentioned model’s parameters, attempting to
replicate the actual cyclic response of a reinforced concrete frame structure. The effect of each
parameter in the hysteresis response will help on the understanding and on the possibilities of this
kind of model in simulating different types of structural systems or different materials.
This paper is within the scope of the first author’s Ph.D. degree in progress, financially
supported by the Portuguese Foundation for Science and Technology (FCT) through the PhD grant
reference SFRH/BD/139570/2018 under the programme POCH (N2020-P2020) and subsidized by
the European Social Fund (FSE) and national funds from MCTES. This work was financially
supported by: Base Funding- UIDB/04708/2020 of the CONSTRUCT-Instituto de I&D em Estruturas
e Construções-funded by national funds through the FCT/MCTES (PIDDAC).
