Passive Control of Liquid Sloshing in Floating Roof Tank With Multi Dynamic Absorber

Abstract

A multi dynamic absorber for suppressing liquid sloshing in a floating roof tank is presented. As well known, many seismic damages on floating roof tanks by the sloshing of their contained liquid due to long periodic components of earthquake motion were reported. Since the natural period of sloshing varies according to the height of liquid surface, robustness for parameters such as natural period is required for the sloshing suppression device to obtain a good suppression performance. From this point of view, we developed a multi dynamic absorber instead of the single dynamic absorber which is sensitive to the parameter variance. A multi degree of freedom mechanical model for sloshing of the contained liquid and the presented multi dynamic absorber which sets up on the floating roof of the tank is derived to design the optimal tuning for parameters of the multi dynamic absorber and to evaluate the sloshing suppression performance. Numerical simulations for an actual size floating roof tank were conducted to examine the performance of the present device. As the result the effect of the presented multi dynamic absorber was effective to suppress the sloshing response of the floating roof and to be robust for the natural period variance.