NEHRP Clearinghouse
- Title
- Dynamic Analyses of Liquid Storage Tanks.
- File
- PB81123275.pdf
- Author(s)
- Haroun, M. A.
- Source
- National Science Foundation, Washington, DC. Engineering and Applied Science., February 1980, 292 p.
- Identifying Number(s)
- EERL-80-04
- Abstract
- The dynamic behavior of cylindrical liquid storage tanks was investigated to improve their ability to resist earthquakes. The study comprised three phases: a theoretical treatment of the liquid-shell system; an investigation of the dynamic characteristics of full-scale tanks; and development of an improved design procedure based on an approximate analysis. Natural vibration frequencies and associated mode shapes were found by using a discretization scheme in which the elastic shell is modeled by finite elements and the fluid region is treated as a continuum by boundary solution techniques. The number of unknowns is substantially less than in those analyses in which both tank wall and fluid are subdivided into finite elements. A method is presented to compute earthquake response of both circular and irregular tanks based on superposition of the free lateral vibrational modes. Numerical examples illustrate the dynamic characteristics of tanks with widely different properties. Ambient and forced vibration tests were conducted on three full-scale water storage tanks to determine their dynamic characteristics. Comparison with previously computed mode shapes and frequencies shows general agreement with experimental results, thereby confirming the reliability of the theoretical analysis. Approximate solutions also were developed to provide practicing engineers with simple, fast, and accurate tools for estimating seismic response of storage tanks.
- Keywords
- Earthquake resistant structures; Storage tanks; Mathematical models; Finite element analysis; Earthquake engineering; Resonant frequency; Cylindrical bodies; Elastic shells; Water tanks; Dynamic structural analysis