Effective tuned mass damper system for RC tall chimney dynamic wind response control

Abstract

Tall chimneys have become necessary due to growing industries and changing environmental norms. Chimneys are tall and slender structures and thus they are sensitive towards wind loads. Thus, it becomes necessary to analyze their performance along both the direction i.e. along the wind and across the wind accurately, and to improve their performance by providing suitable measures. Now a days, Tuned Mass Dampers (TMDs) are provided to improve the performance of structures against dynamic loadings However, there are very few reported studies on the effect of TMDs on wind response control of tall chimneys. Hence, it is important to paper the use of different TMD systems and their performance in chimneys. Two RC chimneys of height of 200 m and 220 m of varying thickness are considered for dynamic wind paper using CFD in ANSYS. Modal response of chimney without and with TMD are also studied. The spring mass analogy is used for the connection of chimney and Tuned Mass Dampers. Gust Factor Method as per IS 875 (III) 2015 and IS 4992-1992, for along and across wind load calculation has been studied. Excel Programme file also prepared for the analysis of wind loads using IS codes. Three TMD systems are considered viz. Single Tuned Mass Damper system (s-TMD) and Multiple Tuned Mass Damper system (m-TMD-1 and m-TMD-2).The analysis results of TMD system are compared with the results of without TMD system. The results are compared on the basis of peak displacements of chimney. It has been found that Multiple TMD systems are more effective than Single TMD system. The reduction in deflection of about 25–30% is observed for m-TMD systems.