The stability analysis and active control of a composite laminated open cylindrical shell in subsonic airflow

摘要

The stability analysis and active control of a composite laminated open cylindrical shell in subsonic airflow are conducted using piezoelectric material. The equation of motion of the shell with piezoelectric patch is derived from Hamilton's principle and transformed into the ordinary differential equations using Galerkin's method. The linear potential flow theory is applied to derive the aerodynamic pressure. The displacement and acceleration feedback control strategies are used to obtain the active stiffness and mass by applying an appropriate external control voltage to activate the piezoelectric patch. The natural frequencies of the system are calculated, from which the flow velocity for the open cylindrical shell under instability can be obtained. The effects of the ply angles of the shell and the feedback control gains on the stability properties of the structural system are discussed. From the results, it can be seen that when the flow velocity becomes sufficiently high, the open cylindrical shell exhibits instability of the divergence type and the instability velocity decreases with the increase in the ply angle. The stability of the system can be improved by the displacement feedback control strategy. With the increase in the displacement feedback control gain, the instability velocity of the system increases. For the acceleration feedback control strategy, the instability velocity of the system remains unchanged, which illustrates that the active mass induced by the acceleration feedback has no effect on the instability velocity of the composite laminated open cylindrical shell.