This paper presents a novel approach for the optimal seismic retrofit of linearly-elastic frame buildings. A unique Single-Input-Multiple-Output (SIMO) general system interconnection (GSI) paradigm is formulated and used to attain structural changes in stiffness and mass in order to reduce the square root of the sum of squares (SRSS) of the absolute acceleration amplification factors. An analogy is drawn between the GSI closed-loop transfer function, having a firstorder general-system-plant and a time-invariant structured controller, and the seismic upgrade at hand. The retrofit procedure itself applies H∞ synthesis to the GSI closed-loop transfer function, by using MATLAB©’s “hinfstruct” function, to design the optimal structured controller. Then, the structural changes in stiffness and mass are extracted from the controller and applied to the linearly-elastic frame buildings. A case-study of a five-story shear-type building is examined. Optimal changes in floor-mass and horizontal-stiffness are obtained and show significant improvement in absolute story accelerations. The results indicate the efficiency of the proposed methodology that possesses the capability of attaining optimal changes in the structure’s physical characteristics of mass and stiffness, while catering for improved performance levels.
|Title of host publication
|16th European Conference on Earthquake Engineering
|Published - 2018