Dynamic Response of Composite Cylindrical Shell Containing Fluid Subjected to Low- Velocity Impact

In this research, for the first time, the dynamic response of a composite cylindrical shells containing fluid filled with different boundary conditions by considering the equivalent weight of the fluid and the equivalent dynamic stiffness of the shell and fluid under low-velocity impact was investigated. The first-order shear deformation theory and the two methods of Rayleigh and beam functions along with the Galerkin weight function were used to solve the governing equations and ABAQUS software was used to validate the results. The main innovation of this research is the use of equivalent dynamic stiffness of the structure containing fluid and equivalent mass of the structure-fluid with a two-degree-of-freedom model of mass and spring to calculate the impact force and interaction between the impactor and the composite shell. The results showed that the various boundary conditions were very effective on the dynamic response of the composite cylindrical shell under low-velocity impact and the presence of fluid reduced the natural frequency of the structure. The difference in the fundamental natural frequency for empty and fluid-filled cylindrical shell was calculated 78%. Parameters such as radius, length and thickness of the shell, different boundary conditions, mass and velocity of impactor are important and influential factors in the study of vibrations, impact phenomenon and structural design.