Free vibration by length-scale separation and inertia-induced interaction -application to large thin-walled structures

Abstract

This paper analyses free vibration of interacting length-scales of 3D-thin-walled structures by combination of Finite Elements Method and analytical calculation of strain and kinetic energies. Equivalent single layer elements with structurally homogenized mass and stiffness enable significantly reduced computational cost. Analytical equations are used to re-introduce effects of inertia-induced deformations of the local length-scale that are restrained by the kinematic of homogenized equivalent single layer elements. The method is validated against fine mesh Finite Element Analysis in a case study representing typical 3D-structure seen in cruise ships. The method achieves excellent accuracy for the 10 first natural modes.