Seismic behavior of knee bracing frame, buckling-restrained brace, and eccentrically braced frame using nonlinear dynamic analysis
Subject Areas : Computer EngineeringMohammad Hadi Eslami 1 , Mohammad Reza Mostakhdemin Hosseini 2 *
1 - Former M.Sc. Student, Department of Civil Engineering, Mahdishahr Branch, Islamic Azad University, Mahdishahr, Iran.
2 - Assistant Professor, Department of Civil Engineering, Mahdishahr Branch, Islamic Azad University, Mahdishahr, Iran.
Keywords: Dynamic analysis, IDA, Energy dissipation and absorption capacity,
Abstract :
In this study, the seismic performance of three bracing systems including knee bracing frame (KBF), buckling-restrained brace (BRB), and eccentrically braced frame (EBF) for steel moment-resisting structures with varying heights (5, 10, and 15 stories) were investigated using nonlinear time-history analysis and incremental dynamic analysis (IDA). The structural models were first designed in ETABS and analyzed under the influence of different earthquakes, including El Centro, Kobe, and Tabas, using nonlinear time-history analysis. The seismic response and optimal bracing system for each scenario were assessed. To further evaluate of the failure conditions and the ductility capacity of the frames, IDA was conducted in Seismostruct. The results indicated that the 5-story frame with a BRB system, the 10-story and the 15-story with a KBF system exhibited the best seismic performance. The IDA curves revealed that the 5-story BRB-braced structure demonstrated limited ductility and experienced brittle failure, with a large number of failed elements. As the building height increased, the structural ductility improved, particularly in the 10-story frame where the use of KBF significantly enhanced the results. For the 15-story frame, combining high ductility and the KBF system resulted in a highly effective seismic response, as evidenced by smooth IDA curve development, indicating a soft and stable structural behavior. Therefore, the KBF system is proposed as a highly suitable option for high-rise buildings to enhance ductility, energy absorption, and dissipation capacity, and to control the yielding and failure of structural members.
[1] Du, K., Cheng, F., Bai, J., & Jin, S. (2020). Seismic performance quantification of buckling-restrained braced RC frame structures under near-fault ground motions. Engineering Structures, 211, 110447.
[2] Katsimpini, P. S., Askouni, P. K., Papagiannopoulos, G. A., & Karabalis, D. L. (2020). Seismic drift response of seesaw-braced and buckling-restrained braced steel structures: a comparison study. Soil Dynamics and Earthquake Engineering, 129, 105925.
[3] Ghowsi, A. F., & Sahoo, D. R. (2020). Seismic response of SMA-based self-centering buckling-restrained braced frames under near-fault ground motions. Soil Dynamics and Earthquake Engineering, 139, 106397.
[4] Sabelli, R.(2001). Research On Improving The Design and Analysis of Earthquake Resistant Steel – Braceed Frames. The 2000 NEHRP Professional Fellowship Report .
[5] Iranian code of practice for seismic resistance design of buildings: Standard no.2800, 4th edition, Building and Housing Research Center, 2014.
[6] Fang, C., Zhong, Q., Wang, W., Hu, S., & Qiu, C. (2018). Peak and residual responses of steel moment-resisting and braced frames under pulse-like near-fault earthquakes. Engineering Structures, 177, 579-597.
[7] Nazarimofrad, E., & Shokrgozar, A. (2019). Seismic performance of steel braced frames with self‐centering buckling‐restrained brace utilizing superelastic shape memory alloys. The Structural Design of Tall and Special Buildings, 28(16), e1666.
[8] Asgarkhani, N., Yakhchalian, M., & Mohebi, B. (2020). Evaluation of approximate methods for estimating residual drift demands in BRBFs. Engineering Structures, 224, 110849.
[9] Yakhchalian, M., Yakhchalian, M., & Asgarkhani, N. (2021). An advanced intensity measure for residual drift assessment of steel BRB frames. Bulletin of Earthquake Engineering, 19(4), 1931-1955.
[10] Hu, S., Wang, W., & Qu, B. (2020). Seismic economic losses in mid-rise steel buildings with conventional and emerging lateral force resisting systems. Engineering Structures, 204, 110021.
[11] Hu, S., & Wang, W. (2021). Comparative seismic fragility assessment of mid-rise steel buildings with non-buckling (BRB and SMA) braced frames and self-centering energy-absorbing dual rocking core system. Soil Dynamics and Earthquake Engineering, 142, 106546.
[12] Iranian national building code for structural loading, (part 6)", ministry of housing and urban development, Tehran, Iran, 2019.
[13] Iranian national building code for RC structure design, (part 9)", ministry of housing and urban development, Tehran, Iran, 2020.