Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.Includes bibliographical references (leaves 66-67).Current trends in structural engineering call for strict performance requirements from buildings prone to extreme earthquakes. Energy dissipation devices are known to be effective in reducing a building's response to earthquake induced vibrations. A promising strategy for controlling damage due to strong ground motion is the use of buckling restrained braces that dissipate energy by hysteretic behavior. Research conducted in the past reveals that devices such as The Unbonded Brace (TM) provide stiffness and damping to the structure, two key parameters that characterize a building's performance. The focus of this thesis is the development of a preliminary motion-based design methodology for the use of these devices in mitigating damage to structural and non-structural elements. In this regard, a shear beam idealization for a typical 1 0-story steel building is adopted and nonlinear dynamic response of the building for a set of earthquakes is simulated. Optimal ductility ratio and stiffness contribution of the bracing system is determined based on the inter-story drift values obtained from simulation results.by Sinan Keten.M.Eng
