Experimental investigation on liquid sloshing in a rectangular container with an elastic cover

We present an experimental study on the natural sloshing frequencies and damping ratios of a liquid-elastic plate coupled system. Two types of edges including complete clamped edges and combined edges (two free and two clamped) are examined. The natural sloshing frequencies measured experimentally agree well with the theoretical predictions. Our findings indicate that the natural frequencies tend to increase with the number of clamped edges with other parameters fixed, while the damping ratio exhibits an opposite trend. Despite the general agreement, there are still minor deviations between analytical solutions and experimental measurements. For combined edges, these deviations increase with liquid depth, whereas for complete clamped edges, they decrease. We attribute these discrepancies primarily to the theoretical assumption that the surface elevation is equal to plate deflection across the entire plate, which is inconsistent with the experimental observation. Furthermore, the rapid decay of the coupled system may also introduce additional measurement errors.