Abstract: (50972 Views)
The main objective of this article is evaluation of the simplified models which have been developed for
analysis and design of liquid storage tanks. The empirical formulas of these models for predicting Maximum Sloshing
Wave Height (MSWH) are obtained from Mass Spring Models (MSM). A Finite Element Modeling (FEM) tool is used
for investigating the behavior the some selected liquid storage tanks under available earthquake excitations. First, the
results of FEM tool are verified by analyzing a liquid storage tank for which theoretical solution and experimental
measurements are readily available. Then, numerical investigations are performed on three vertical, cylindrical tanks
with different ratios of Height to Radius (H/R=2.6, 1.0 and 0.3). The behaviors of the tanks are initially evaluated using
modal under some available earthquake excitations with various vibration frequency characteristics. The FEM results
of modal analysis, in terms of natural periods of sloshing and impulsive modes period, are compared with those
obtained from the simplified MSM formulas. Using the time history of utilized earthquake excitations, the results of
response-history FEM analysis (including base shear force, global overturning moment and maximum wave height)
are compared with those calculated using simplified MSM formulations. For most of the cases, the MSWH results
computed from the time history FEM analysis demonstrate good agreements with the simplified MSM. However, the
simplified MSM doesn’t always provide accurate results for conventionally constructed tanks. In some cases, up to
30%, 35% and 70% average differences between the results of FEM and corresponding MSM are calculated for the
base shear force, overturning moment and MSWH, respectively.