Free dynamic analysis of a launcher
This study has been performed for a future application to a reusable lunar launcher in the perspective of NASA's new project of a Lunar Orbital Platform-Gateway. In order to carry out this project, a reusable launcher will be required to deliver an certain payload from the moon to the lunar station and return. A fundamental step of this launcher project will certainly be its dynamic study. In this contest this paper uses different finite element approaches to carry out the free vibration analysis of a simplified model of a launcher. The 1D refined models, that are used in the present work, are based on the Carrera Unified Formulation (CUF), which assumes a variable kinematic displacement field over the cross-sections of the beam. Thanks to the compact form of the displacement field approximation, governing equations are written in terms of fundamental matrices. The frequencies and the natural modes obtained using the refined one-dimensional (1D) beam model are compared to those obtained by a commercial finite element software Nastran. Three different structures were teken into account: a simple square beam, a thin-walled beam, a simple model of launcher.