Large-amplitude vibrations of thick cantilevered circular cylindrical shells containing still fluid

Abstract

In the present study, for the first time, thick and moderately thick shells with clamped-free boundary conditions are modeled according to the third-order shear theory with thickness stretch. Then using Lagrange relations, the governing differential equations of the system in terms of shell–fluid​ interaction are derived and the solution method of the equations is also presented. The linear and nonlinear free vibration of cantilevered circular cylindrical shell containing quiescent fluid is investigated and the effects of shell thickness, length and fluid relative height are studied. In linear free vibration analysis, it was observed that the presence of fluid reduces the fundamental frequency of the system and the number of circumferential waves of the fundamental mode, especially in the thin shell. Also, increasing the height of the fluid, strengthens the decreasing fundamental frequency of the system. In nonlinear analysis, it was found that the presence of fluid, mainly weakens the nonlinear behavior in the thin/thick shell. Also, it was found that with increasing shell thickness, the effect of fluid on the nonlinear behavior of the system decreases, and the shell behavior is more dominant in the system. In addition, the presence of fluid has mainly reduced the peripheral contraction of the shell caused by the large amplitude circumferential waves, so that peripheral contraction approaches zero in the fully filled thin shell.