eVTOL flutter analyses in wingborne flight via ground vibration test data and actuator failure effects on stability

This study investigates flutter of electric vertical take-off and landing aircraft in wingborne flight by directly integrating ground vibration test data for the suspended (free-body) structure, applicable for such class of aerial vehicles, with a detailed aeroelastic analysis including potential control surface failures. A state-space representation is constructed using a rational function approximation of the generalized aerodynamic force matrix. A change-of-basis approach is employed to transform the aerodynamic forces from a numerical model to align with experimental modes, incorporating modal parameters such as frequencies and masses to develop the aeroelastic model. Furthermore, the model enables a robust evaluation of flutter susceptibility under potential failure scenarios by integrating the inertial, elastic, and aerodynamic effects of control surface deflections, refined through finite element properties. The proposed approach allows to directly use the experimental data provided by the modal analysis for flutter analysis and related eigensensitivity to control surface stiffness reduction. • The novel aeroelastic framework uses GVT data for eVTOL aircraft operating in wingborne flight. • A change-of-basis method enables projecting aerodynamic loads onto experimentally identified structural modes. • Experimental modal parameters combine with an RFA for unsteady aerodynamics in a state-space aeroelastic model. • The hybrid numerical–experimental approach enables flutter prediction under control surface failures.