http://www.iaeme.com/IJCIET/index.asp 72 editor@iaeme.com International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 2, February 2017, pp. 72–88 Article ID: IJCIET_08_02_008 Available online at http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=2 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed SEISMIC RESPONSE OF UNSYMMETRIC BUILDING WITH OPTIMALLY PLACED FRICTION DAMPERS S. S. Sanghai Assistant Professor, Civil Engineering Department, G. H. Raisoni College of Engineering, Nagpur, India S. N. Khante Associate Professor, Applied Mechanics Department, Govt. College of Engineering, Amravati, India ABSTRACT Conventional methods of seismic rehabilitation with concrete shear walls or steel bracing are not considered suitable for some buildings as upgrades with these methods would have required expensive and time consuming foundation work. Supplemental damping in conjunction with appropriate stiffness offers an innovative and attractive solution for the seismic rehabilitation of such structures. This paper deals with the use of friction damper as a passive dissipative device in order to seismic retrofit of existing structures and discusses the optimal placement criteria. To fulfill this objective, six storey and ten storey L-shaped buildings have been modeled with five different damper location formats in SAP2000 subjected to El Centro and Utterkashi earthquake records. Non-Linear Modal Time History Method has been used for the analysis and base shear, joint displacement, member forces and hysteresis energy has been compared to find out most optimal damper location format. Key words: friction damper, non-linear modal time history analysis, optimization, slip load Cite this Article: S. S. Sanghai and S. N. Khante, Seismic Response of Unsymmetric Building with Optimally Placed Friction Dampers. International Journal of Civil Engineering and Technology, 8(2), 2017, pp. 72–88. http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=2 1. INTRODUCTION Severe ground shaking induces lateral inertial forces on buildings, causing them to sway back and forth with amplitude proportional to the energy fed in. If a major portion of this energy can be consumed during building motion, the seismic response can be considerably improved. The manner in which this energy is consumed in the structure determines the level of damage. The use of bracing systems equipped with dissipative devices is relatively new technique for the earthquake protection of buildings that has been considered in several recent experimental and theoretical studies. In particular, the friction damping bracing system involving the device proposed by Pall and Marsh (1982) has been carefully analyzed, since its simplicity of construction and high dissipative capacity encourages application in practice. At present, the existing studies offer