2025 Volume 81 Issue 13 Article ID: 24-13511
Bulging is a coupled vibration between tank wall and content fluid. This phenomena is induced by seismic ground motion. In general, water tanks are divided into two parts by partition plates. There is a case of water leakage due to damage to partition plates caused by the bulging. In this study, to clarify the mechanism of bulging in the partition plate and analyze its effects, vibration experiments and finite element analysis are conducted on an acrylic rectangular model tank with a two-compartment structure. First, the natural frequencies of the side walls and partition plate are estimated based on the results of vibration experiments and eigenvalue analysis. Subsequently, a time-history response analysis is conducted utilising the aforementioned natural frequencies, thereby corroborating the reproducibility of the vibration experiment results. This enables the replication and characterisation of bulging in the partition plate. Finally, water pressure acting on the side walls and partition plate is calculated from the time history response analysis results, and the pressure distributions are compared. As a result, it is found that the current design guidelines may not hold during resonance with the partition plate.
