Optimal Placement of Friction Dampers in High Rise Buildings Under Seismic Excitation

Abstract

In the optimal design of damper placement in buildings, various methods exist. and of such methods exists different forms of algorithms for the optimal placement of damping devices. The use of such algorithms is sometimes complex and design engineers would need accurate and simple to use methods to determine the best placement of damping devices. The method proposed in this paper aims to address this. This is achieved by using the shear deformation of the building as the main criteria of damper placement since the shear deformation is easily computed. With the shear deformation known, the dampers can be sequentially placed throughout the building. In this paper, the design of a ten (10) storey building frame is investigated as a case study using optimally placed friction. The responses are obtained in the time domain using a nonlinear time history analysis of seven (7) random ground motions records. The analysis was run using 3D FEM software alongside a computational routine developed in the Python programming language. The optimal locations of the dampers are found using the sequential search algorithm using the grid shear deformation as the placement criterion. It is shown that the performance of the frame, before and after the use of the friction dampers is greatly improved and a reduction in the time required for the analysis. Furthermore, the optimal placement of dampers is sensitive to the type of seismic excitation and device parameters of friction dampers namely the slip load.