Project

VIBRATION CONTROL OF FRAME STRUCTURE USING MULTIPLE TUNED MASS DAMPERS

ABSTRACT

Need for taller structure in construction and real estate industry is increasing all over the world. These structures are flexible and constructed as light as possible (as seismic load acts on a structure is a function of self-weight), which have low value of damping, makes them vulnerable to unwanted vibration. This vibration creates problem to serviceability requirement of the structure and also reduce structural integrity with possibilities of failure. Current trends use several techniques to reduce wind and earthquake induced structural vibration. Passive tuned mass damper (TMD) is widely used to control structural vibration under wind load but its effectiveness to reduce earthquake induced vibration is an emerging technique. Here a numerical study is proposed on the effectiveness of tuned mass damper to reduce translation structural vibration. Total three type of models, i.e., shear building with single TMD, 2D frame with single TMD and 2D frame with double TMD are considered. Total five numbers of loading conditions are considered named sinusoidal ground acceleration, EW component of 1940 El-Centro earthquake (PGA=0.2144g), compatible time history as per spectra of IS-1893 (Part -1):2002 for 5% damping at rocky soil (PGA=1.0g), Sakaria earthquake (PGA=1.238g), The Landers earthquake (1992) (PGA=1.029g) for time history analysis of considered model.

The effectiveness of single TMD to reduce frame vibration is studied for variation of mass ratio of TMD to frame. Also the effect of double tuned mass damper on the frame response is studied for uniform, non uniform distribution of mass ratio and variation of damping ratio of damper.

From the study it is found that effectiveness of TMD increases with increase in mass ratio. Use of double TMD is much more effective than single TMD of same mass ratio for vibration mitigation under earthquake as well as sinusoidal acceleration.