Session: DA-22-01 Design and Analysis of Above Ground Liquid Storage Tanks

Paper Number: 151681

151681 - Elastic Analysis on Above Ground Liquid Storage Tank With Variable Liquid Fill Levels 

Abstract: 

The analytical model from an earlier study on the above ground liquid storage tank is further developed to include all liquid fill levels. Using general elasticity theory, the tank is modeled as an axisymmetric structure with a cylindrical wall and a flat floor at bottom. As a preliminary study, the earlier model only considered the shell at or below the liquid level inherent in the normalized coordinate used in developing the equations, which effectively restricted the model to a full or nearly full tank. For a partially filled tank, this may generate problem since the shell and its stiffness above the liquid level were ignored. As a continued effort from the previous study, the model is further expanded by introducing a separate parameter on liquid level. Separate governing differential equations are laid out for shell sections pending if a section is above or below the liquid. Additionally, for tank wall with multiple shell courses, a generalized form of solution equations is derived for all shell courses by properly defined step functions on liquid condition for a shell course, regardless of its position to the liquid level. Thus, a tank under any liquid load capacity, either full or partially filled, is permitted. The expanded model follows the same boundary conditions used in earlier work. For the elastic constraints at the corner joint, equations developed previously for parameters of equivalent torsional and radial displacement springs are still utilized. The modified matrix equations for all liquid fill conditions are presented. Results of a tank loaded with liquid to different capacities are compared to finite element analysis. This updated work provides a complete analytical method for a tank under any liquid fill levels.

Presenting Author: Mingxin Zhao Enterprise Products

Presenting Author Biography: Mingxin Zhao, Ph. D.

Current Employment:
SME & Senior Staff Engineer
Facility Mechanical Integrity Engineering
Enterprise Products
Houston, Texas

Education:
Ph.D. in Applied Mechanics
University of Maryland
College Park, Maryland

Authors: