STRUCTURAL DYNAMICS ASSESSMENT ON A FULL-ELECTRIC AIRCRAFT: GROUND VIBRATION TESTING AND IN-FLIGHT MEASUREMENTS

Aircraft electrification is going to radically change the air transportation in the future.
Being a new technology, it is very important to assess the vibroacoustic behavior of an
electric aircraft in order to provide useful information to the design and manufacturing teams on
the end-products acoustic and dynamic performances. In this paper an assessment based on the
structural dynamics characteristics has been carried out both on the ground and in-flight on the
Magnus eFusion, first all-electric aerobatic training airplane in the world. Both challenges and
findings related to lightweight aircrafts Ground Vibration Testing (GVT) and in-flight measurements
for flutter analysis are discussed. The GVT, required for flutter prediction analysis and
Finite Element model update, is typically scheduled very late in the development process, right
before the final painting and the maiden flight, in a short time window with the aircraft readyto-
fly: high quality and representative frequency response functions are compulsory and testing
time is a constraint. This paper describes a GVT campaign carried out at the Magnus facilities
in Hungary where several innovative processing techniques and control algorithms have been
used for obtaining the experimental modal model of the full aircraft. Special focus has been
given to novel processing techniques with the additional target to identify potential structural
nonlinearities by the mean of tailored excitation signals. The results from the GVT campaign
have been then used to prepare the in-flight tests. In-flight vibration measurements have been
performed with a reduced number of sensors for various flight conditions in order to assess the
risk to enter into aerodynamic flutter. Finally the comparison between GVT mode shapes and
in-flight ones has been performed.