Experimental Modal Analysis of an Aircraft Wing Prototype for SAE Aerodesign Competition

Abstract

This work presents an experimental modal analysis of an aircraft wing prototype, designed by the Aerodesign team of the University of Brasilia, and performs a ground vibration testing of the prototype. The dynamic response data were acquired using the software LabVIEW, and the modal parameters were identified through the EasyMod toolbox. The modal parameters are characterised for the first seven vibration modes of the structure, with the firsts two being suspension modes of vibration. The effect of small changes in the experimental procedure on the identified modal parameters is discussed. It was observed that the use of an excitation signal as a logarithmic sine sweep and with a frequency range of excitation between 2 to 150 Hz resulted in less noise and more accurate measurement of the structure’s response. Results for different modal identification methods were verified using the Modal Assurance Criterion (MAC), and good correlation was achieved.

Control surface design for radio-controlled aircraft. Case: SAE Aero Design Micro-class prototype

“…Although programs based on numerical methodologies can be time-consuming in the development of simulations, they provide increasingly accurate results. For instance, the dynamic response data of modal analyses in aircraft's structures can be identified through numerical methodologies as in [17]. Flow analysis by means of CFD is an alternative to carrying out expensive experimental tests performed, for example, with fully developed flows with high Reynolds numbers [18].…”