FE Modelling of Vibrational Parameters of Viscoelastic CNT-CFRP Hybrid Spherical Shell Structures

PurposeVariable thickness plates are commonly seen in aircraft wings, turbine disks and reinforcement sheets. The dynamic properties of the variable thickness plates in the aerodynamic environment and subjected to external excitations are significant for the safety and optimal design of these structures.MethodsIn this paper, the stability and nonlinear vibration of variable thickness plates are investigated. Based on the nonlinear plate theory and linear potential flow theory, the coupling equations of variable thickness plate and subsonic airflow are established. The subsonic aerodynamic stability is analyzed by calculating the inherent frequencies of the system at different airflow velocity speeds, and the nonlinear dynamical behavior of the system is analyzed by the incremental harmonic balance method (IHB).ResultsThe effects of airflow velocity, taper coefficient, and thickness variation form of the variable thickness plate on vibration stability and nonlinear vibration behaviors are discussed. In the study, novelty nonlinear dynamic properties such as the hard nonlinear phenomena, loopback linearity, and internal resonance phenomena can be observed, and the stability of the vibration becomes worse when the airflow velocity, taper coefficient, and form of variation are varied.ConclusionsThe study can provide some suggestions for the optimal design of variable thickness plates in aerodynamic environments.

Automated summary

This paper investigates the stability and nonlinear vibration of variable thickness plates. Based on nonlinear plate theory and linear potential flow theory, the coupling equations of variable thickness plates and subsonic airflow are established. The study analyzes the subsonic aerodynamic stability by calculating the inherent frequencies at different airflow velocities and analyzes the nonlinear dynamic behavior using the incremental harmonic balance method (IHB).