Full Aircraft Dynamic Response by Simplified Structural Models

摘要

The finite element method (FEM) is widely used in the structural analysis of aircraft. In order to investigate the static and dynamic response of the whole structure different models are used: one-, two- and three- dimensional models. A new approach in the aircraft structural analysis is presented in this paper. A formulation for one- two- and three-dimensional higher order models is introduced by means of the Carrera Unified Formulation (CUF).The CUF allows to develop refined theories where the order of expansion is a free parameter of the problem. The FEM is used to solve the problem in order to deal with any geometries and boundary conditions. The present model (CUF+FEM) is used to investigate some typical aircraft structure first considering the aircraft as a single beam with a non-uniform cross-section, and then by considering the aircraft built by different beams, one for each part of the aircraft (fuselage, wing, etc...). Two- and three- dimensional elements are used as 'node' in order to overcame the problem related to the assembling of higher order beams. In this work a simplified aircraft model is investigated. The different models considered are compared in terms of natural frequencies. The results show that the present model is able describe properly the aircraft dynamic response, by reducing the degrees of freedom (DOFs) needed in the analysis respect to the commercial code.