Optimum sizing design of steel frame structures through maximum energy dissipation of friction dampers under seismic excitations

Abstract

This paper focuses on optimum sizing design of steel frame structures equipped with friction dampers (FDs) in order to prevent the vulnerable effect of an earthquake. The fundamental concept is to maximize the energy dissipation of implemented FDs under different seismic excitations. The FDs utilized as passive energy dissipation devices in a steel structure increase the energy dissipation capacity of the structure by decreasing the seismic demand during an earthquake. In this context, the Pall friction dampers (PFDs) are implemented as diagonal damped brace members in investigated structures. Three different earthquake records (Kobe, Kocaeli-Duzce, Erzincan) are utilized to acquire nonlinear dynamic responses of the steel frame structures through time-history analyses. The open application programming interface (OAPI) functions are used to integrate a finite element modelling based structural analysis program, SAP2000, with a design optimization algorithm encoded in MATLAB for achieving the exact structural behaviours by synchronously data transferring. As an optimizer, one of the recent nature-inspired metaheuristic techniques, so-called Grey Wolf (GW) algorithm is used. Initially, under effect of seismic excitations, the steel frame structures are optimally sized for attaining minimum design weights without implementing the PFD elements by subjecting only strength, displacement, drift, and geometric structural design constraints taken from AISC-LRFD practice code provisions. Afterward, in order for optimally modelling the PFD elements, the frames are equipped with PFDs to calculate optimum yield strengths that is defined as slip load of a PFD. To do so, the GW algorithm ensures the maximizing of the dissipated energy and controls the yield strengths between the stories since the shear force due to the earthquake increases towards the base of the structure. Eventually, the provisions-based sizing design optimizations of the steel frame structures equipped with optimally modelled PFD elements are conducted under seismic excitations for conclusive evaluations.