Vibration characteristic modeling of FG-GOEAM-RM joined conical-cylindrical shell: experimental verification and theoretical research

In the field of aerospace, conical-cylindrical shell connection structure is the key design to realize the integration of aerodynamic shape and bearing demand of aircraft. The global mode vibration behavior is analyzed for the functionally graded graphene origami-enabled auxetic metamaterials reinforced metal (FG-GOEAM-RM) joined conical-cylindrical (JCC) shell by semi-analytic method. The artificial springs are introduced at both ends and joints of JCC shells to achieve arbitrary boundaries and connection relations. When the spring stiffness tends to infinity, it corresponds to the case of fixed support at both ends and rigid connection between two shell segments. The material parameters of the FG-GOEAM-RM in JCC shell are precisely controlled by using a micromechanical model supported by genetic programming. The frequencies and mode shapes of JCC shell are determined based on the Chebyshev polynomials and Rayleigh-Ritz method. Through comparative verification with modal experiments, Ansys Workbench simulations, and results from the existing literature, the accuracy of the modeling approach presented in this paper is fully demonstrated. Parametric investigations examine the effects of spring stiffness, graphene folding degree, graphene content, and gradient pattern on the natural frequencies. This study offers practical guidance for the optimal design of FG-GOEAM-RM JCC shells in aerospace engineering.