FEM based aeroelastic modeling of Very Flexible Aircraft

Student : Cristina Riso

Sponsor : Sapienza – Università di Roma (Sapienza University of Rome)


Highly flexible aircraft experience large-amplitude deflections at low natural frequencies, which cause nonlinear coupling between rigid-body and elastic degrees of freedom. Integrated models of coupled nonlinear aeroelasticity and flight dynamics are thus necessary for effective design, simulation, and control of very flexible vehicles. Although low-order unique models are available based on geometrically-exact beam formulations and two-dimensional aerodynamics, it is of interest to develop general approaches to fully exploit the higher-fidelity modeling capabilities of 3D nonlinear FEM, UVLM, and CFD codes.

The scope of this project is to develop and implement a FEM-based integrated methodology for high-fidelity analysis of very flexible aircraft. Three progressive levels of complexity are considered: linearized, statically-nonlinear, and fully-nonlinear modeling. As a main advantage, the proposed approach can easily integrate standard codes for structural dynamics and steady/unsteady aerodynamics, so being suitable to analyze complex aircraft configurations. The University of Michigan X-HALE vehicle – a highly flexible UAV for nonlinear aeroelastic tests – is considered as test case to assess the methodology.

FEM model of the X-HALE (provided by M. Ritter).
VLM model of the X-HALE (provided by M. Ritter)