Vibration frequency design and study of composite fuselage structure

The influence of various physical properties of composite materials on the natural vibration frequency of the cylindrical shell is studied. On this basis, an equivalent design method is proposed, which takes the vibration frequency and node position of composite fuselage structure as the design objective. Firstly, an equivalent model for isotropic material is established aiming at resolving two typical problems about position on modal nodes and deformation frequency. Secondly, through the design of experiments, the effects of the elastic modulus and Poisson's ratio of the composite on the beam free vibration frequency of the cylindrical shell and correlations among these parameters and natural frequencies are discussed. Finally, genetic algorithm is used to design the composite fuselage structural layout in detail based on the equivalent stiffness model. The dynamic index of the composite fuselage and target values are within acceptable limits, which verifies the correctness of the design idea of active fuselage structural stiffness.