Probabilistic Nonlinear Finite Element Analysis of Elevated Tanks Under Seismic Loads Fluid-Soil-Structure Interaction
Volume Title: ICASGE2025
Paper ID : 1057-ICASGE-FULL
Authors
Abstract
Many liquid storage tanks have suffered different levels of damage during earthquakes. Seismic analysis of such tanks becomes complicated due to the fluid – structure interaction (FSI). Furthermore, when the soil properties are taken into considerations; the analysis with fluid – soil – structure interaction (FSSI) becomes rather complicated and tedious.
A mechanical model that captures the features of elevated tanks and reflects the FSSI phenomenon is employed in this study since a 3D model of the tank, fluid and soil requires huge computer resources and takes much time to perform the nonlinear analysis due to the large number of degrees of freedom. Nonlinear finite element dynamic time-history analysis is carried out using ANSYS program. Three design earthquakes with three different frequency contents; high, medium and low frequency contents are selected for the analysis in order to cover a wide range of possible earthquakes.
Probabilistic analysis is conducted considering the soil properties as the random variables. This is conveniently done by coupling ANSYS with MATLAB mathematical package in order to access the Monte Carlo simulation routine within MATLAB.
The results show that the probabilistic analysis gives valuable information and expectation about the behavior of elevated tanks due to changes of soil properties.
A methodology is delineated in order to assess the probability of failure of such tanks due to overloading effects in the presence of several probabilistic variables
A mechanical model that captures the features of elevated tanks and reflects the FSSI phenomenon is employed in this study since a 3D model of the tank, fluid and soil requires huge computer resources and takes much time to perform the nonlinear analysis due to the large number of degrees of freedom. Nonlinear finite element dynamic time-history analysis is carried out using ANSYS program. Three design earthquakes with three different frequency contents; high, medium and low frequency contents are selected for the analysis in order to cover a wide range of possible earthquakes.
Probabilistic analysis is conducted considering the soil properties as the random variables. This is conveniently done by coupling ANSYS with MATLAB mathematical package in order to access the Monte Carlo simulation routine within MATLAB.
The results show that the probabilistic analysis gives valuable information and expectation about the behavior of elevated tanks due to changes of soil properties.
A methodology is delineated in order to assess the probability of failure of such tanks due to overloading effects in the presence of several probabilistic variables
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