Determining the Optimal Length of Link Beam in Eccentric Braced Frames under Near and Far-fault Earthquakes

Document Type : Research Paper

Authors

1 Assistant Professor, Department of Civil Engineering, University of Eyvanekey, Semnan, Iran

2 MSc, Department of Civil Engineering, University of Eyvanekey, Semnan, Iran

3 Ph.D. Candidate, Faculty of Engineering, Department of Civil Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran

Abstract

In this research, it will be paid to evaluate the effects of the link beam length on seismic behavior of eccentric braced frames under near and far-fault earthquakes. For this purpose, four frame structures with different number of stories such as 3, 6, 9 and 12 have been used. For each of these frames, three different lengths of link beam are considered. After designing structures and preparation of non-linear models, these models are analyzed under a suite of 10 and 3 near and far-fault records, respectively. Nonlinear dynamic time history analyses are performed using scaled records for these structures, and the response values of the stories displacement, base shear and the rotation of link beam are evaluated for them. Based on the results of this study, it is specified that increasing the length of link beam and change the mode of the link beam from the shear to bending, the values of stories drift are considerably increased, but the values of base shear are decreased relatively. This result is similar for near and far-fault records. Therefore, it seems that the use of a short link beam would offer a better behavior to the braced frame if the architectural conditions allow. The results showed that in 0.8 m as an optimal length, the displacement response of frames under near-fault records up to 15 percent larger than the far-fault records. This difference is lower for base shear response.

Keywords

References

[1]- Mohebkhah, A., Chegeni, B., 2014, Overstrength and rotation capacity for EBF links made of European IPE sections, Thin-Walled Structures, 255-260.
[2]- Caprili, S., Morelli, F., Mussini, N. and Salvatore, W., 2018, Experimental tests on real-scale EBF structures with horizontal and vertical links. Author’s Accepted Manuscript, Data in Brief.
[3]-Vetr, M. Gh., Ghamari, A., and Bouwkamp, J., 2017, Investigating the nonlinear behavior of Eccentrically Braced Frame with Vertical shear links (V-EBF), Journal of Building Engineering, 23-45.
[4]- Danesh Ashtiyani, A., and Naserifar, A., 1396, Numerically investigation of the behavior of long link to column connections with reduced section, Modelling in Engineering (JME), 152-156.
[5]- Raissi Dehkordi, M., Alizadeh, M., and Eghbali, M., 1395, Seismic Evaluation of Steel Moment Frames Rehabilitated with CBF, EBF and BRBF Braced Systems, Modelling in Engineering (JME), 96-100.
[6]- Adlparvar, M., 1389, Optimized Analysis and Design of the link Beam with Eccentrically Braced Frame. Modelling in Engineering (JME), 152-156.
[7]- Hejazi T., Rahimi bandar abadi, H. and Hossein, A., 1394, Analytical study of seismic performance of EBF link systems. Tehran, Second National Iranian Structural Engineering Conference, 89-93.
[8]- Rosario, M. Elide, N., Vincenzo, P., 2016, Theory of Plastic Mechanism Control for MRF–EBF dual systems: Closed form solution, Elsevier, Engineering Structures, 288-292.
[9]- EN 1998-1. Eurocode 8, 2004, design of structures for earthquake resistance – Part 1: general rules, seismic actions and rules for buildings. CEN.
[10]- CSI 2007. SAP 2000: integrated finite element analysis and design of structures. Analysis reference, Berkeley: Computer and Structure Inc.,University of California.
[11]- Code-No.360, 1385, Instruction for Seismic Rehabilitation of Existing Buildings, Management and Planning Organization of the country – I.R.I.
[12]- Seismosoft, 2016, SeismoStruct - A computer program for static and dynamic nonlinear analysis of framed structures, Available from URL: www.seismosoft.com
[13]- Peer ground motion database. All earthquake record that used. [Online] Available at: https://ngawest2.berkeley.edu/ [5/5. 1396].
[14]- Standard No: 2800, 1393, Iranian code of practice for seismic resistant design of buildings, permanent Committee for Revising The Iranian Code of Practice for Seismic Resistant Design of Buildings. 4th edition.
[15]- Seismosoft [2016] "SeismoSignal - A computer program for signal processing of time-histories". Available from URL: www.seismosoft.com
[16]- Khalili, S., Meshkodini, A., and Ghamsari, J. K., 1396, Seismic performance of high rise hybrid structures with moment frame configuration, Journal of structural and construction engineering, 1(11), 88-97.
[17]- Mozzafari jooybari, Y., Mahmoodi, Y. and Maghsoodian, Sh., 1391, investigating the performance of EBF steel frames under earthquake near the fault seismic load, Babolsar: Second national conference of structures, earthquakes, geotechnic, 112-113.
[18]- Farahan, S., and Mohebkhah, A., 1394, Overstrength of Displacement-Based Designed Eccentrically Braced Steel Frames, Journal of structural and construction engineering, 4(5), 48-61.
[19]- Zare, M., Khoshmood, A., and Shekasteband, B., 1394, Analysis of the sensitivity coefficient of the steel eccentric braced frame behavior with respect to the number of story and the span width, 3rd National & 1st International Conference in applied research on Civil Engineering, Architecture and Urban Planning.
New Approaches in Civil Engineering
Volume 4, Issue 4
March 2021
Pages 78-97

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