Disordered honeycomb panels optimized to minimize structural impacts of non-stationary loadings on aircraft and aerospace components – DIZZY

The concept of Anderson localization has an untapped potential that could help improve aerospace and transport engineering by enabling the development of lightweight and robust materials capable of mitigating non-stationary dynamic loadings of high energy. Initially developed to explain the metal-insulator transition in pure metals, the phenomenon was soon found to be ubiquitous in all wave equations for disordered media. However, despite the theoretical and experimental studies on Anderson localization in various fields and models/equations developed over more than half a century, practical applications for designing new materials and structures are still rare, especially in the field of vibroacoustics. The DIZZY project brings together expertise covering theoretical, numerical, and experimental aspects to address the challenge of isolating structural components from high-energy elastic waves in the aerospace and transport industry.
Periodic honeycomb (HC) structures have a high stiffness-to-weight ratio, making them the go-to solution in that industry. Their periodic cellular microstructure can enter into complex interference with the elastic waves, such as scattering, attenuation, filtering, and possibly the appearance of frequency band gaps where the wave propagation is stopped. Unfortunately, these frequency band gaps are often narrow, and small uncontrolled manufacturing defects can further decrease their width, making classical HC structures poor shock absorbers. The DIZZY project aims to address the challenge of high-frequency elastic wave propagation in aerospace and transport components by leveraging the concept of Anderson localization by means of a tailored disorder in HC networks. The project's goal is to enable structures to deflect the impact of loading away from critical areas.
The duration of the project is 48 months, with a Ph.D. thesis (36 months) and two post-doctoral studies (24 and 12 months, respectively). The theoretical work involves developing analytical models for understanding Anderson localization in disordered HC structures by proposing techniques to construct dispersion relations in such media. The numerical work focuses on simulating the behavior of HC structures under dynamic loads using a discontinuous Galerkin solver in the time domain, coupled with a surrogate model creation for fast design exploration. The experimental work involves manufacturing and testing HC sandwich panels with the tailored disorder. Using laser vibrometry equipment and high-intensity non-stationary dynamic loads, we will attempt to quantify the effect of Anderson localization in the developed structures.
At the end of the project, a helicopter model will be equipped with a sandwich trim panel and monitored under dynamic load constraints. By demonstrating the practical applications of Anderson localization, the DIZZY project has the potential to pave the way for future progress in the aerospace and transport industries, where disorder was previously only seen as a source of efficiency loss. To change this paradigm, the partner team aims to propose new designs with improved capacity at annihilating the vibrational energy transport by waves over large frequency bands while advancing basic research to understand better the effect of disorder on the dynamical behavior of HC sandwich panels and the underlying mechanisms.
Ultimately, the DIZZY project seeks to design materials and structures that will make aerospace vehicles more lightweight, more robust, and more capable of withstanding non-stationary dynamic loadings.