EFFECT OF MASS IRREGULARITIES ON THE RESPONSE OF BUILDING UNDER SEISMIC EFFECT

Abstract

If a building has irregular distribution in mass, strength and stiffness or any combination of these then the building may be called as an irregular building. The irregularity limits are found to be different in different codes. Many times irregularity in building may be intentionally provided due to functional and aesthetic considerations. However past earthquake records indicate that these building have not performed well in seismic excitation condition. Research works undertaken in the past indicate that location of an irregularity in a structure is an important parameter. In the present study mass irregularity in an aluminium frame is considered. The mass irregularity is created by applying additional mass at different floor level. The eigenvalue analysis is calculated of the framed model. The calculated eigenvalue is compared with those from commercial Etabs software. In the present study it shows that the variation of mass along the height of the building affects the floor displacement of the building. The dynamic characteristics of the buildings are affected by the location of mass irregularities. Experimental results are validated by those obtained from the consideration of mathematical models of Etabs.