IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, PP 01-07 www.iosrjournals.org International Conference on Emerging Trends in Engineering & Management 1 |Page (ICETEM-2016) Comparative Study On Seismic Behaviour Of Steel Knee Braced Frame With Eccentric Braced Frame Anitha M 1 , Divya K.K 2 1 M.Tech Scholar, Department of Civil Engineering, SN Gurukulam College of Engineering, Ernakulam,India 2 Assistant Professor, Department of Civil Engineering, SN Gurukulam College of Engineering,Ernakulam,India Abstract: The great strength, uniformity, light weight and many other desirable properties makes steel the material of choice for numerous structures such as steel bridges, high rise buildings, towers and other structures. Steel structures situated in high seismic activity should be stiff enough to limit the drift and should have enough ductility to prevent collapse. Bracing technique is one of the economic method for resisting seismic activity. In this steel bracing provides an effective and economical solution for resisting lateral forces in a framed structure. Knee braced steel frame is that which has got excellent ductility and lateral stiffness. Since the knee element is properly fused, yielding occurs only to the knee element and no damage to major elements. Compared to other type of bracings it performs better during a seismic activity. In this study the configuration of knee braced had been arrived. And after that a comparison of knee braced steel frame with eccentric bracings had been done. Performance of both the frames had been studied using non-linear static analysis and non linear time history analysis. Various parameters such as displacement and stiffness were studied. Keywords - Displacement,Non linear static analysis , Non linear time history analysis, Steel bracing, Stiffness. I. Introduction Bracing element in structural system plays vital role in structural behavior during earthquake. Steel bracing is an effective and economical solution for resisting lateral forces in a framed structure. Compared to all other bracings, knee bracings have got excellent ductility and stiffness. Frames with knee bracings (KBFs) provide an effective bracing solution. It can be obtained by providing a new element called "knee" in between the beam and column along with bracings. These bracings limit interstorey drifts, and knee element absorbs the earthquake energy, by providing cyclic deformations in shear or bending. The main advantage with respect to eccentric braced frames is that damage is concentrated in secondary element and it can easily be replaced after destructive earthquakes. The first step in designing a knee braced moment frame is to design the base moment frame using any valid design method. After the determination of beams and columns dimensions, the knee braces dimensions are to be fixed so that the yielding of knee braces and formation of plastic hinges in the intermediate beams and column bases during a seismic activity. The position and stiffness of knee was the most important factor affecting the lateral resisting ability of KBF.The beams and columns got great influence on the lateral behaviour of KBF structure [6]. The knee element will yield first without affecting the other main structural elements [7]. Fig.1. Knee bracing