NEHRP Clearinghouse
- Title
- Earthquake Response of Sea-Based Storage Tanks by a Hybrid Element Method-Theory and Computer Analysis.
- File
- PB82104993.pdf
- Author(s)
- Lee, S. C.; Ko, D. R.
- Source
- National Science Foundation, Washington, DC., March 1981, 214 p.
- Identifying Number(s)
- DT-7814-2
- Abstract
- An effective method for the linear analysis of dynamic response of submerged underwater oil storage tanks to loadings of earthquake excitations is presented. The tank is axisymmetric in shape and has a flexible wall/roof. A general hybrid-finite element solution procedure has been formulated, wherein the tank structure, the interior fluids, as well as the near field of the exterior water region, are discretized into a toroidal mesh network. The tank displacement is expressed as a superposition of the first few modes of the structure's free vibration. Contribution from the hydrodynamic interaction to the coupled motion is obtained by solving the Laplace equation with the appropriate boundary conditions, which includes a match to the exterior far-field pressure (analytic) representation to simplify the computational process. The effects of fluids surrounding and inside the tank are studied. It is demonstrated that these effects are, in general, significant to the tank earthquake response analysis. A comprehensive and predictive computer program for use in such tank response analysis is developed for design engineering applications.
- Keywords
- Seismic design; Earthquake resistant structures; User needs; Storage tanks; Underwater structures; Dynamic response; Finite element analysis; Earthquake engineering; Oil storage; Computer programs; ERST computer program; Hydrodynamics; Earthquakes