Dynamic Characteristics of Liquid Storage Tanks

A reliable and computationally effective method for calculating the dynamic characteristics of ground-supported cylindrical tanks is developed. The method offers a rigorous treatment of the interaction problem and provides a starting point for the consideration of the complicating factors which influence the dynamic behavior of tanks. The liquid region is treated analytically and only the shell is modeled by finite elements. In this approach, the number of unknowns is substantially less than in those analyses where both tank wall and liguid are subdivided into finite elements. The reliability of the analysis is illustrated by computing modes and natural frequencies of full-scale tanks and comparing them with the results of vibration tests. The effectiveness of the method has led to a development of an improved seismic design procedure for tanks.