On stability and active control of carbon nanotube reinforced material moving thin cylindrical shell
摘要
Aircraft like missiles and rockets often operate under high-speed motion and hygrothermal conditions, potentially affecting their stability and threatening structural safety and performance. Therefore, this research models missiles and rockets as axially moving cylindrical shells, and investigates the stability and active control of simply supported (S–S) cylindrical shells undergoing axial motion, subject to hygrothermal conditions and reinforced with carbon nanotubes (CNTs). Employing Love’s classical shell theory and the principle of Hamilton, the mathematical model for an axially moving piezoelectrically hierarchical shell enhanced with CNTs subject to hygrothermal effects is developed. The Galerkin discretization scheme is further adopted to reduce the dynamic equations to a finite-dimensional system. Macro fiber composites (MFC) were integrated as controller components, bonded to the internal and external surfaces of the shells. Control systems are designed using linear quadratic regulator (LQR) and displacement feedback controller (DFC) strategies to suppress the shell displacement under unstable conditions. We examine how nanotube distribution, volume fraction, power-law index, cylindrical shells thickness, temperature and humidity affect the shell’s critical velocity. Simulation results indicate that both control strategies can effectively enhance dynamic stability, with the LQR method demonstrating superior performance in vibration suppression. For the design of mobile shell structures that must perform reliably in complex settings, these findings offer valuable insights.