Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Hybrid braced frame with buckling-restrained and strong braces to mitigate soft story
Abstract The steel concentric braced frames (CBFs) are the common structural system for buildings. Unlike high strength and stiffness, brace buckling in CBFs results in high nonlinear behavior, which causes damage concentration in one or a few stories during a severe earthquake. This paper proposes a hybrid CBF bracing system to reduce soft-story mechanisms and improve the structural behavior of the CBF system. The proposed system is composed of a buckling restrained brace (BRB) or an energy dissipation device and a strong brace (SB) in one span. The strong braces are designed to have an elastic performance during an earthquake. The direction of BRB and SB are changed, inversely, story by story in a zigzag form. This configuration leads to paradoxical results: stiffness and ductility. This improves both the soft story mechanisms and the buckling capacity of CBFs. In this study, a set of 6-story structural models with different bracing patterns including inverted-V, multi-X, zipper, hexa (hexagonal bracing configuration), and strongback braced frames were evaluated through nonlinear static (pushover) and dynamic analyses (IDA). The collapse performance of structural models was assessed by comparing the seismic behavior of conventional CBFs with similar bracing configuration based on FEMA P695 criteria. From the evaluation of collapse fragility curves, the hybrid bracing system had more safety margin against collapse during severe earthquakes than conventional CBFs.
Highlights A hybrid CBF system is conducted to mitigate soft story mechanism. The Hybrid CBF combines two Buckling Restrained Brace (BRB) and Strong Brace (SB) systems in one bay and is called Concentric BRB-Strong Braced Frame (CBSBF). In this system, BRB is used to balance compression and tension forces, and SB is designed to behave elastically during strong earthquakes. The direction of BRB and SB are changed, inversely, story by story, and the braces locate in a zigzag form on the frame to reduce drift concentration. Various bracing configurations including inverted-V brace (IVBF), multi-X brace (XBF), zipper (ZBF), hexabrace (HBF) and strongback braced frames (SBF) are considered to evaluate the structural response of proposed system.
Hybrid braced frame with buckling-restrained and strong braces to mitigate soft story
Abstract The steel concentric braced frames (CBFs) are the common structural system for buildings. Unlike high strength and stiffness, brace buckling in CBFs results in high nonlinear behavior, which causes damage concentration in one or a few stories during a severe earthquake. This paper proposes a hybrid CBF bracing system to reduce soft-story mechanisms and improve the structural behavior of the CBF system. The proposed system is composed of a buckling restrained brace (BRB) or an energy dissipation device and a strong brace (SB) in one span. The strong braces are designed to have an elastic performance during an earthquake. The direction of BRB and SB are changed, inversely, story by story in a zigzag form. This configuration leads to paradoxical results: stiffness and ductility. This improves both the soft story mechanisms and the buckling capacity of CBFs. In this study, a set of 6-story structural models with different bracing patterns including inverted-V, multi-X, zipper, hexa (hexagonal bracing configuration), and strongback braced frames were evaluated through nonlinear static (pushover) and dynamic analyses (IDA). The collapse performance of structural models was assessed by comparing the seismic behavior of conventional CBFs with similar bracing configuration based on FEMA P695 criteria. From the evaluation of collapse fragility curves, the hybrid bracing system had more safety margin against collapse during severe earthquakes than conventional CBFs.
Highlights A hybrid CBF system is conducted to mitigate soft story mechanism. The Hybrid CBF combines two Buckling Restrained Brace (BRB) and Strong Brace (SB) systems in one bay and is called Concentric BRB-Strong Braced Frame (CBSBF). In this system, BRB is used to balance compression and tension forces, and SB is designed to behave elastically during strong earthquakes. The direction of BRB and SB are changed, inversely, story by story, and the braces locate in a zigzag form on the frame to reduce drift concentration. Various bracing configurations including inverted-V brace (IVBF), multi-X brace (XBF), zipper (ZBF), hexabrace (HBF) and strongback braced frames (SBF) are considered to evaluate the structural response of proposed system.
Hybrid braced frame with buckling-restrained and strong braces to mitigate soft story
Mashhadiali, Niloufar (Autor:in) / Saadati, Siamak (Autor:in) / Mohajerani, Seyed Amir Mohammad (Autor:in) / Ebadi, Parviz (Autor:in)
22.02.2021
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
| British Library Conference Proceedings | 2004
Seismic demands on steel braced frame buildings with buckling-restrained braces
| Online Contents | 2003
Seismic demands on steel braced frame buildings with buckling-restrained braces
| British Library Conference Proceedings | 2003