Identification of Flexible Structures Dynamics

The pursuit of aerodynamic efficiency and the advances in materials technology, particularly in composite material, has contributed to shifting the paradigm of wing design to high aspect ratio wings. Increasing the span, for decreasing drag, and using composite lightweight materials make the new wing very flexible and prone to non-linear dynamic behaviour. Thus, increasing challenges arise for the identification and modelling of the wing. It is fundamental to expand the knowledge of the behaviour of these structures through the identification and modelling of sample flexible wing models, with the possibility for the expansion of design and analysis tools.

In this seminar, a series of methods and approaches are presented for the identification and modelling of flexible wings. First, a system identification technique in the frequency domain, the Loewner Framework, is applied for modal parameters extraction in mechanical systems for structural health monitoring. Then, a thorough, linear and non-linear, vibration test campaign on a flexible wing model for the detection, identification and quantification of non-linearities is presented. Finally, a meta-model technique based on Kriging, the refined Efficient Global Optimisation, is proposed for finite element model updating and damage detection.

The results presented show that a deeper knowledge of the structural dynamic behaviour of flexible structures can be obtained with a mix of novel computationally efficient techniques and state-of-the-art experimental and that these new techniques can pave the way to the full exploitation of the dynamics of flexible structures.