Eigenmodes Solution and Analysis of Combined Structures Using Improved Coupling Energies

Abstract

In this paper, improved coupling energies are developed for the vibration analysis of combined structures having coordinate systems in different directions. The in-plane and transverse vibration displacements for the combined structures are expanded as improved Fourier series to ensure the continuity and smoothness of the series representation in the solution domain. The energy principle is adopted to solve the eigenmodes of various combined structures, including the open box coupled structure and enclosed box-type coupled structure. The eigenmodes of the enclosed box-type structure, three-plate coupled structure, and four-plate coupled structure are compared with ones obtained from FEM, and good agreement is observed. The validations of the eigenmodes for the combined structures connected at an arbitrary included angle are analyzed in numerical analysis. The influence of the modal characteristics of the open box structures composed of five plates are studied for different boundary conditions.