Vibration analysis of laminated composite cylindrical shells with various fibre orientations

This paper investigates the vibration behaviour of simply-supported laminated composite cylindrical shells with various fibre orientations. For some specific fibre orientations, theoretical wave propagation approach based on Love’s theory is used for free vibration analysis of the laminated orthotropic composite cylindrical shells. The circumferential natural frequencies have been obtained and compared with numerical finite element results for validation and comparison. The finite element method is employed for the forced vibration analysis of laminated composite cylindrical shells with various fibre orientations subjected to harmonic loading. The results show that natural frequencies, mode shapes and the steady-state response at prescribed points can be tailored by properly designing fibre orientations for vibration mitigation. It is found that fibre orientations may have significant influence on the circumferential natural frequencies of the first few circumferential modes. For the first two circumferential modes, the associated natural frequencies may increase with fibre orientation angle. In comparison, the natural frequencies of larger circumferential modes may decrease with fibre orientation angle. The steady-state responses of cylindrical shells under a harmonic concentrated force are obtained. The variations of the resonance frequencies and corresponding peak value of steady-state response with fibre orientations have been investigated. The findings could improve the understanding of dynamic behaviour of the laminated composite cylindrical shells, and benefits optimisation of the fibre orientations for vibration suppression purpose.