Investigation of free and forced vibration of a composite circular cylindrical shell with internal fluid

The present study was aimed at investigating the vibration of composite cylindrical shell filled with internal liquid with simple two-headed boundary conditions. The shell was composed of multilayer composite. First-order shear theory was employed to solve the governing equations of the shell. First loves approximation theory was utilized to write strain-displacement and curvature-displacement equations. Natural frequencies of the composite cylindrical shell filled with fluid were calculated using minimum potential energy principle. The fluid was supposed to be ideal. According to the equations that were obtained through analytical solution, a computerized code was written using MATLAB software in order to achieve an answer for analyzing the vibrations of the shell. In order to make sure about the precision of the results, the composite cylindrical shell was modelled in Abacus Software, and modal analysis was carried out for it. Moreover, the effect of different parameters such as presence of fluid, the density and height of the fluid, the orientation of the fibers, and some geometrical parameters on the natural frequencies of the shell were investigated in empty and filled states of the shell. The transient dynamic response of the composite cylindrical shells filled with internal liquid that was under lateral impulse load was calculated through the principle of mode superposition. Finally, the effect of stable load and motivation frequency on the vibrations of the composite cylindrical shell was examined.