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Seismic Behaviour of Steel Frames Investigation with Knee Brace Based on Pushover Analysis

Authors: Mahmoud Miri, Abdolreza Zare, Hossein Abbas zadeh


The knee bracing steel frame (KBF) is a new kind of energy dissipating frame, which combines excellent ductility and lateral stiffness. In this framing system, a special form of diagonal brace connected to a knee element instead of beam-column joint, is investigated. Recently, a similar system was proposed and named as chevron knee bracing system (CKB) which in comparison with the former system has a better energy absorption characteristic and at the same time retains the elastic nature of the structures. Knee bracing can provide a stiffer bracing system but reduces the ductility of the steel frame. Chevron knee bracing can be employed to provide the desired ductility level for a design. In this article, relation between seismic performance and structural parameters of the two above mentioned systems are investigated and compared. Frames with similar dimensions but various heights in both systems are designed according to Iranian code of practice for seismic resistant design of building, and then based on a non-linear push over static analysis; the seismic parameters such as behavior factor and performance levels are compared.

Keywords: Seismic behaviour, ordinary knee bracing frame, Chevron knee brace, behaviour factor, performance level.

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[1] M. Mofid, M. lotfollahi, "On the Characteristics of New Ductile Knee Bracing System," journal of Constructural Steel, Research 62, 2006, pp 271- 281
[2] C. W. Roeder and E. P. Popov, "Eccentrically Braced Steel Frames for Earthquakes," J.Struct. Div. ASCE, 104(ST7), 1978, pp 391-411
[3] J. D. Aristizabal-Ochao, "Disposable Knee Bracing: Improvement in Seismic Design of Steel Frames," J. Struct. Engng., ASCE, No. 7, 112, 1986, pp 1544-1552.
[4] T. Balendra, M. T. Sam, and C. Y. Liaw, "Diagonal Brace with Ductile Knee Anchor for Aseismic Steel Frame," Earthquake Engng. Struct. Dyn., No. 6, 19, 1990, pp 847-858.
[5] T. Balendra, Lim EL, Lee SL, "Ductile Knee Braced Frames with Shear Yielding Knee for Seismic Resistant Structures," Engineering Structures , 1994, Vol 16(4), pp 263-9.
[6] P. Khosravi and M. Mofid, "Non-linear analysis of disposable knee Bracing," Computers and Structures 75, 2000, pp 65-72
[7] M. Mofid, and P. Khosravi, "Non-linear analysis of dispoable knee Bracing,"Computers & Structures, 75, 2000, pp 65-72.
[8] Chia-Ming Uang,"Establishing R (OR RW) and Cd Factors for Building Seismic Provisions," Journal of Structural Engineering, Vol. 117, No. 1, January, 1991
[9] N. M. Newmark and W. J. Hall, "Seismic Design Criteria For Nuclear Reactor Facilities," Report No.46, Building Practices for Disaster Mitigation, National Bureau of Standards, U.S. Department of Commerce, 1973, pp.209- 236.
[10] E. Miranda, "Site Dependent Strength Reduction Factor," ASCE, Journal of Structural Engineering, Vol.119, No.12, 1993.