Energy balance assessment of tall buildings equipped with friction dampers for earthquake response control

Abstract

Seismic analyses and energy balance assessment of a two-dimensional (2D) moment-resistant frame (MRF), a braced frame (BF), and a friction damped frame (FDF) are reported in the present study. The mathematical formulations for various forms of energies in the MRF, BF, and especially in the FDF are presented. These multi-storey steel frames have been modelled with lumped masses on each floor and massless columns in each storey. Four such frames with 5, 10, 15, and 20 storeys are subjected to three different earthquake ground motion time histories to calculate various energies, such as the input energy, energy dissipated in structural damping, energy dissipated by the friction damper, strain energy, and kinetic energy. The results obtained for the MRF, BF, and FDF are assessed to investigate the effectiveness of the friction damper. It is observed that the friction damper dissipates significant amount of energy imparted by the seismic ground motion, which considerably reduces the demand of structural damping in the tall buildings. Furthermore, the kinetic and strain energies in the FDF diminish more rapidly than that in the MRF and BF, which signifies improved seismic performance of the tall buildings equipped with the friction dampers.