Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames

The process of seismic retrofitting for inadequate RC frames is vital for enhancing structural integrity in areas susceptible to earthquakes. This research investigates a novel tube-in-tube (TnT) buckling restrained brace (BRB) system aimed at improving the seismic performance of these substandard R...

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Main Authors: Evrim Oyguc, Resat Oyguc, Onur Seker, Abdul Hayır, Jay Shen, Bulent Akbas
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/15/9/4662
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author Evrim Oyguc
Resat Oyguc
Onur Seker
Abdul Hayır
Jay Shen
Bulent Akbas
author_facet Evrim Oyguc
Resat Oyguc
Onur Seker
Abdul Hayır
Jay Shen
Bulent Akbas
author_sort Evrim Oyguc
collection DOAJ
description The process of seismic retrofitting for inadequate RC frames is vital for enhancing structural integrity in areas susceptible to earthquakes. This research investigates a novel tube-in-tube (TnT) buckling restrained brace (BRB) system aimed at improving the seismic performance of these substandard RC frames. By targeting significant weaknesses inherent in older RC constructions, the TnT BRB introduces a lightweight, all-steel configuration that eliminates the need for traditional mortar or concrete infill materials. Experimental shake table testing on two one-third scaled RC frame models was conducted to compare the seismic performance of an unretrofitted control frame and a frame retrofitted with the TnT BRB system. Results indicate significant enhancements in lateral strength, ductility, and energy dissipation capacity in the retrofitted frame, demonstrating stable and symmetrical hysteresis loops and reduced stiffness degradation compared to conventional X-braced systems. Analytical modeling corroborated these experimental findings, confirming the TnT BRB’s superior capability in absorbing seismic energy and preventing premature structural failures. This investigation emphasizes both the practical and financial benefits of integrating the TnT BRB into seismic retrofitting strategies while recommending further research to optimize the system, specifically addressing issues related to local denting, frictional wear, and alignment to bolster its effectiveness in practical applications.
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institution Kabale University
issn 2076-3417
language English
publishDate 2025-04-01
publisher MDPI AG
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series Applied Sciences
spelling doaj-art-a8668d4b21f74d4694398b5bc8daaac62025-08-20T03:49:22ZengMDPI AGApplied Sciences2076-34172025-04-01159466210.3390/app15094662Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC FramesEvrim Oyguc0Resat Oyguc1Onur Seker2Abdul Hayır3Jay Shen4Bulent Akbas5Institute of Disaster Management, Istanbul Technical University, Maslak 34469, Istanbul, TurkeyInstitute of Disaster Management, Istanbul Technical University, Maslak 34469, Istanbul, TurkeyCivil Engineering Department, Gebze Technical University, Gebze 41400, Kocaeli, TurkeyCivil Engineering Department, Istanbul Technical University, Maslak 34469, Istanbul, TurkeyConstruction and Environmental Engineering, Department of Civil, Iowa State University, Ames, IA 50011-2011, USACivil Engineering Department, Gebze Technical University, Gebze 41400, Kocaeli, TurkeyThe process of seismic retrofitting for inadequate RC frames is vital for enhancing structural integrity in areas susceptible to earthquakes. This research investigates a novel tube-in-tube (TnT) buckling restrained brace (BRB) system aimed at improving the seismic performance of these substandard RC frames. By targeting significant weaknesses inherent in older RC constructions, the TnT BRB introduces a lightweight, all-steel configuration that eliminates the need for traditional mortar or concrete infill materials. Experimental shake table testing on two one-third scaled RC frame models was conducted to compare the seismic performance of an unretrofitted control frame and a frame retrofitted with the TnT BRB system. Results indicate significant enhancements in lateral strength, ductility, and energy dissipation capacity in the retrofitted frame, demonstrating stable and symmetrical hysteresis loops and reduced stiffness degradation compared to conventional X-braced systems. Analytical modeling corroborated these experimental findings, confirming the TnT BRB’s superior capability in absorbing seismic energy and preventing premature structural failures. This investigation emphasizes both the practical and financial benefits of integrating the TnT BRB into seismic retrofitting strategies while recommending further research to optimize the system, specifically addressing issues related to local denting, frictional wear, and alignment to bolster its effectiveness in practical applications.https://www.mdpi.com/2076-3417/15/9/4662structural resilienceshake table testingtube-in-tube buckling restrained braces
spellingShingle Evrim Oyguc
Resat Oyguc
Onur Seker
Abdul Hayır
Jay Shen
Bulent Akbas
Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames
Applied Sciences
structural resilience
shake table testing
tube-in-tube buckling restrained braces
title Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames
title_full Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames
title_fullStr Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames
title_full_unstemmed Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames
title_short Experimental Evaluation of an Innovative Tube-in-Tube Buckling Restrained Braces for Seismic Retrofitting of Substandard RC Frames
title_sort experimental evaluation of an innovative tube in tube buckling restrained braces for seismic retrofitting of substandard rc frames
topic structural resilience
shake table testing
tube-in-tube buckling restrained braces
url https://www.mdpi.com/2076-3417/15/9/4662
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