Hajirasouliha, I., Pilakoutas, K. and Mohammadi, R.K. (2016) Effects of uncertainties on seismic behaviour of optimum designed braced steel frames. Steel and Composite Structures: An International Journal, 20 (2). pp. 317-335. ISSN 1598-6233
Abstract
Concentrically braced steel frames (CBFs) can be optimised during the seismic design process by using lateral loading distributions derived from the concept of uniform damage distribution. However, it is not known how such structures are affected by uncertainties. This study aims to quantify and manage the effects of structural and ground-motion uncertainty on the seismic performance of optimum and conventionally designed CBFs. Extensive nonlinear dynamic analyses are performed on 5, 10 and 15-storey frames to investigate the effects of storey shearstrength and damping ratio uncertainties by using the Monte Carlo simulation method. For typical uncertainties in conventional steel frames, optimum design frames always exhibit considerably less inter-storey drift and cumulative damage compared to frames designed based on IBC-2012. However, it is noted that optimum structures are in general more sensitive to the random variation of storey shear-strength. It is shown that up to 50% variation in damping ratio does not affect the seismic performance of the optimum design frames compared to their code-based counterparts. Finally, the results indicate that the ground-motion uncertainty can be efficiently managed by optimizing CBFs based on the average of a set of synthetic earthquakes representing a design spectrum. Compared to code-based design structures, CBFs designed with the proposed average patterns exhibit up to 54% less maximum inter-storey drift and 73% less cumulative damage under design earthquakes. It is concluded that the optimisation procedure presented is reliable and should improve the seismic performance of CBFs.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Techno-Press. This is an author produced version of a paper subsequently published in Steel and Composite Structures: An International Journal. |
Keywords: | Monte Carlo simulation; optimum seismic design; concentrically braced frame; seismic performance; non-linear behaviour |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Civil and Structural Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 04 Mar 2016 16:14 |
Last Modified: | 26 Jul 2022 14:37 |
Published Version: | http://dx.doi.org/10.12989/scs.2016.20.2.317 |
Status: | Published |
Publisher: | Techno-Press |
Identification Number: | 10.12989/scs.2016.20.2.317 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:92320 |