Study of Passive Energy Dissipation Devices for Seismic Resistance of Structure

Abstract

During an earthquake a large amount of energy is imparted into the structure. To reduce the response of structure undergoing vibrations it becomes important for the structure to absorb or dissipate the energy. Historically, aseismic design has been based upon a combination of strength and ductility. For small, frequent seismic disturbances, the structure is expected to remain with in elastic range, with all stresses below yield level. However, it is not reasonable to expect that a traditional structure will behave elastically when subjected to a major earthquake. Design considerations rely on inherent ductility of building to prevent catastrophic failure, which may render the building non functional after the earthquake. The actual dynamic nature of environmental disturbances demands more advanced structural protective systems. Structural protective system can be divided into three major groups, Passive Energy Dissipation Devices, Semi-active and Active Systems. The present study is an attempt to understand the behavior of energy dissipation devices in addition to inherent structural damping of the R.C.C frame building. Two types of dampers namely Viscous and Viscoelastic were undertaken as additional damping members. The modeling and analysis of R.C.C building with attached dampers was done through commercially available software SAP-2000 (Version 9.1).The analysis methodology adopted was Response Spectrum Method based on IS:1893-2002 (Part-I). Various parameters like Displacement, Drift, Base shear, Force carried by the dampers and energy dissipation capacities were studied in detail. In addition to these, parameters like influence of variation of storey height, temperature variation, location and cost of damper was also calculated. At last comparative study of viscous and viscoelastic damper has been done. It was observed that about 25% of the Lateral load was carried by the dampers with only 5% additional damping. It was also found that displacement response of the structure reduces to a considerable extent.