Seismic performance of steel moment frames with variable friction pendulum systems under real ground motions

Year 2018, Volume: 2 Issue: 3, 208 - 216, 15.12.2018

Ahmet Hilmi Deringöl

Abstract

Many researchers have already
acknowledged that the base isolation system as the most feasible and economical
method for civil engineering structures exposed to the seismic excitation. The
Friction Pendulum Systems (FPS) have steel concave surface connected with
articulated friction slider and utilized the concept of pendulum for
lengthening the period of the superstructure so as to dissipate the seismic
energy. The present study investigates on various design approaches for the
evaluation of the seismic response of steel frames equipped with FPS. The
response of isolated frames is simply adjusted by several parameters such as
the friction coefficient (μ), the radius of curvature (R), the isolation period
(T) and the axial load and so 2D, three bay 3 and 7-storey steel moment
resisting frames (SMRF) are designated as isolated frames in order to examine
the effect of variation of the R and the friction coefficient on the seismic
response of the isolated frames. The R and μ are predefined as 1, 1.55, 2.25
and 0.025, 0.05, 0.1, respectively. The seismic response of the modelled
isolation systems has been evaluated through nonlinear time history analyses, a
set of ground motions using SAP2000 software. The local and global deformations
are employed to compare the seismic performance of different isolation frames
through nonlinear analysis. The results showed that the isolated frames having
greatest radius of curvature with lowest friction coefficient exhibited better
seismic performance than other models in terms of the local and global
deformations.

Keywords

Friction pendulum systems, Isolator response model, Seismic isolation, Time history analysis

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