Effect of a Long-Duration Irregular Excitation on the Dynamic Behavior of a Vertically Baffled Base-Isolated Rectangular Fluid Container

Abstract

The dynamic behavior of a partially filled rectangular fluid container isolated by nonlinear hysteretic bearing is numerically investigated. The computational fluid domain with the presence of a submerged vertical baffle is modeled based on a velocity potentialbased Galerkin's finite element method. The competency of the developed model is verified with the existing results. A long-duration irregular harmonic motion is imposed for the time domain analysis. The results indicate that the isolation system has excellent adaptability for different tank-fluid-baffle configurations and is very effective in controlling critical dynamic responses of the fluid tank such as hydrodynamic base shear and sloshing amplitudes. The peak values of the hydrodynamic responses for base-isolated and non-isolated tanks are evaluated for different heights and widths of the submerged baffle, where the effect of change in h/d ratio has a significant impact on the variation in sloshing amplitude and base shear responses as compared to the change in w/L ratio. The application of base isolation reduces the sloshing amplitudes by 12 to 34% in different configurations of the baffle except at h/d=0.5. The base shear is also reduced by 2 to 48% in base-isolated tanks depending upon different baffle configurations. The isolator displacement is invariably found to be maximum when h/d=0.5, irrespective of the width of the baffle.