Dynamic Characterization of a Flexible Wing Model Using Stochastic ModalAppropriationforNonlinearAeroelasticAnalysis

In modern aerospace engineering, the push for lightweight and flexible wings aims to enhance efficiency, reduce fuel consumption, and enable adaptation to extreme flight conditions. These flexible structures undergo large deformations, highlighting a need for validated nonlinear numerical models, making Operational Modal Analysis (OMA) essential for dynamic characterization in environmental conditions. This study applies the Stochastic Modal Appropriation (SMA) method to a flexible wing model inspired by the Pazy Wing, built and tested at the University of Rome ”La Sapienza”. SMA estimates modal parameters using the correlation function as an impulse response under white noise excitation. The goal is to demonstrate the effectiveness of the SMA method even when natural frequencies are closely spaced, as observed in the Pazy wing. The method effectively captures the flutter mechanism, characterized by a hump mode where the first torsional frequency approaches the second bending mode. However, compared to other MDOF OMA techniques, SMA shows discrepancies, particularly in damping estimation.