A study on the effects of hydraulic static load on the dynamic characteristics of the partially liquid-filled cylindrical shell

Abstract

Liquid storage container is a kind of significant structure in aerospace engineering. In this study, experiments are performed to investigate the dynamic characteristics of the partially liquid-filled cylindrical shell. Modal tests are carried out to study the influence of liquid on bulging frequency of the container. With the increment of liquid level, bulging frequencies of the coupled system decrease obviously. Modal shape interchange is observed, which is leaded by that the mode distribution become denser due to the additional mass effect. Numerical method is employed to validate the experimental phenomena, and the results are in good agreement with the test results. Models with thinner sidewalls are also considered in, and the effects of static load on the system frequency are divided into two parts to discuss, namely, deflection effect and initial stress effect. Calculated results indicate that the static load affects the system’s stiffness mainly in the form of initial stress, and deflection can hardly affect the shell’s stiffness. The bulging frequency of the system is obviously increased compared to the results without static load effects. For the extreme thin shell, when both initial stress and additional mass are taken into consideration, the bulging frequency of almost filled thin-walled container will be non-sensitive to the liquid level’s change.