Elliptical deformation of floating roof pontoon by second mode resonance: Nonlinear sloshing analysis of cylindrical liquid storage tank with single-deck type floating roof part 2

This paper investigates the behavior of the second mode resonance in the liquid storage tanks with the single-deck type floating roof. In theTokachi-Oki Earthquake in 2003, the floating roof of the large-sized oil tanks received damage by sloshing. One of the reasons is considered to beelliptical deformation of the pontoon by the second mode resonance in the past report. In this paper, the behavior of the floating roof is simulatedby the numerical analysis method which we propose, and the deformation and stress in the pontoon are investigated in detail. The stress of thepontoon calculated by the design method notified by the Fire Defense Agency is compared with the numerical results. By these results, thevalidity and the applicability of the design method are discussed.