Placement of Damper for Seismic Response Control of RC Building

Abstract

Earthquake produces a disastrous dynamic force on structural systems. The dynamic force is responsible to cause damage to various structural elements or parts of structure and even has potential completely collapse the structure. Understanding of behaviour of structural system to such dynamic force is of prime important, so as structural systems can be made earthquake resistant. Dynamic structural response resulted due to dynamic forces can be controlled by three di erent approach, namely Passive Control, Active Control and Hybrid Control. The response is primarily control by providing various dampers, which acts either passively or actively. Presently, structural response is controlled by employing passive damper is widely accepted in practice, since they produce resistance damper force by structural motions itself and thus does not require any external energy. The prime focus of the present study is to evaluate e ectiveness of placement of passive damper in a building. A three storey shear building is considered here. Mass and sti ness matrices for the building are obtained considering lumped mass model. Rayleigh damping is assumed considering 5% of critical damping for all modes. A building is subjected to four di erent types of excitation namely, El Centro (1940), Loma Prieta (1989), Northridge (1994), and Kobe (1995). All possible combination for passive control devices (viscous and viscoelastic damper) are considered for a building, i.e. possible location and nos. of dampers are considered. Equation of motion for each possible combination of damper location and their nos. are derived. Response quantities like displacement, velocity, acceleration, inter storey drift and damper force are extracted for uncontrolled building (without passive damper) and controlled building (with passive damper) using MATLAB. Comparison among response quantities of uncontrolled building and controlled building shows that later shows moderate reduction in all response quantities. Parametric study compares of di erent value of damping coe cient for viscous damper and viscoelastic damper are also carried out. The results shows out of various placement of damper considered, damper placed on each oors works most e ectively and reduce responses when only one damper is to be used, results shows damper placed at ground floor provide good response in all response quantities.