Refined Mass Modelling in FEM for Aeroelastics Purposes: An Industry Approach

摘要

The purpose of this study is to review different approaches to improve the current standard of FEM mass modelling for aeroelastics and dynamics processes in the aircraft industry. A range of options currently under investigation are suggested: improved lumped mass methods, a density approach and nodal mass modelling. In order to assess the merits and also, no doubt, problems of each of them three industrial cases are proposed: 1. Fuselage Mass Modelling: the Modal Assurance Criterion (MAC) is used to compare numerical simulations against Ground Vibration Test (GVT) results for validation purposes. 2. Wing mass modelling: same approach as for the fuselage but now targeting wing mass distributions. 3. Elevator mass modelling: flutter analysis is used to assess the impact of the different ways of modelling mass with same overall properties. While assessing these methodologies, we also evaluate the feasibility of their industrial use, as well as the main issues encountered. The more relevant one, the proliferation of spurious modes when more refined mass models are applied on standard FEM models, is described and some potential solutions are also suggested.