Frequency trajectory and modal analysis of variable stiffness composite cylindrical shells with flange

Variable stiffness composite structures show great application potential due to their flexible spatial stiffness adjustment ability. In this paper, the accurate and efficient dynamic models of variable stiffness composite cylindrical shells considering the effects of the flange are established based on a semi-analytic frame. Then, the finite element models of the corresponding structures are established by using the ANSYS commercial software. Through the comparison of the calculation results between models under two analytical frameworks, the correctness and efficiency of the proposed modeling method are well verified and reflected. In addition, an instant hammering test of a composite cylindrical shell with flange is carried out to verify the accuracy of the modeling method at the experimental level. Then, the influence of design parameters on frequency trajectories and modals of the variable stiffness composite cylindrical shell with flange is studied. The analysis results show rich and interesting phenomena, among which, the circumferential variable stiffness composite cylindrical shell with and without flange exhibits complex frequency veering behavior under continuous variations of design parameters. The research work has a certain guiding significance for the dynamic optimization design of the variable stiffness composite cylindrical shell with flange.