Designability analysis of the dynamics of thin-walled carbon fiber laminated shells based on varying the lay-up angle and number of plies

Finite element software was used to model the scaling dynamics of a composite-laminated shell of a solid rocket motor to investigate the modal frequencies of a thin-walled carbon fiber laminated shell. The accuracy of finite element simulations was verified through modal experiments. The effect of the lay-up angle and number of plies on the modal frequency of thin-walled carbon fiber laminated shells was investigated, and the corresponding empirical equations were determined. The results revealed that at each order, the variation in the modal frequencies of the composite-laminated shells was due to a change in the lay-up angle for a provided ply. The maximum frequency variation reached 276 Hz, and the modal frequencies of the shells changed when the number of layers varied from 5 to 10 when the total wall thickness of the shell remained constant. Furthermore, changes in the lay-up angle resulted in a pronounced effect on the modal frequencies of the shells of all orders. The expected modal frequencies and vibration patterns of laminated shells of thin-walled carbon fibers were obtained by varying the lay-up angle with the number of layers.