Characterization of Passive Energy Dissipating ADAS Metallic Damper

Abstract

Earthquakes are one of the major natural hazards to life on the earth and have affected countless areas on almost every continent. The damage caused by earthquakes are mostly seen in man-made structures which are most of the time responsible for most of the causalities. Therefore, it is necessary that structures are designed to resist earthquake forces, in order to reduce the loss of life. Passive control devices were developed the earliest and have been used more commonly in practice for seismic design. Hysteretic dissipators shows the yielding of metals or sliding. In metallic dampers seismic energy is dissipated through in-elastic deformation of metals. Metallic dampers utilize the yielding of metals as the dissipative mechanism. In the present study, characterization of ADAS type metallic damper is carried analytically and experimentally to understand cyclic behaviour. It is found that response of metallic damper is a function of its geometry and its mechanical characteristics of the metal. Study of different types of metallic damper which are experimented or researched in history is also been done for this work. The primary factors affecting ADAS element behaviour are device elastic stiffness, yield strength and yield displacement. Attempt has been made to develop a step-wise design procedure for ADAS type metallic damper in Indian Scenario. Design procedure is verified by performing original design of ADAS metallic damper done by researchers in literature. For analysis of considered problem programming tool MATLAB, SAP2000 as well as ABAQUS is used. For extraction of yield displacement of considered portal frame pushover analysis of a Portal Frame is done using SAP2000. Results of frame without damper is also compared with results of model made in SAP2000 commercial software for different time history data. From yield displacement of a structure required design of an ADAS Metallic damper is been carried out and modelled in FEM software ABAQUS to characterize its damping properties and mechanical properties. Further it is implemented in considered system of portal frame system both SDOF and MDOF systems. Displacement responses are extracted using Newmark Beta method to solve equation of motion of a system for different time history data. Both the responses of frame with and without metallic damper is compared and due to additional damping and additional stiffness added in system, decrement in response is observed. Experimental setup is also been proposed with 3D diagrams and 2D diagrams with proper dimensions and drawing. ADAS type of X-plate Metallic Damper is also been designed for doing experiment considering all values of Shake Table which is also proposed to use for experimental work.