Session: 01-02-03: Phononic Crystals and Metamaterials

Paper Number: 150424

150424 - Advanced Fem Investigation of Acoustic Properties in Sandwich Structures With Metamaterial Core for Aerospace Applications 

It is well known that, to compete in the global market, the design of modern aircraft is driven by the continuous improvement of the safety and cabin comfort. The surrounding environment and particularly noise and vibration (N&V) can deeply affect passengers and pilots in cabin and cockpit, especially during long haul flights. On the other hand, spacecraft and its payload are subjected to high structural vibrations, during launch phase, that are crucial in view of the overall success of a spacecraft’s mission. In this sense, reducing the acoustic loads plays a significant role in cost optimization of the mission. A possible solution to the problem of noise is the conception of high-performance acoustic treatments for the trim panels of aerospace vehicle.

An overarching challenge is the design of 2D structures capable of providing exceptional sound insulation on a wide frequency range, especially in the aerospace field where the materials are required to obey several criteria that usually clash with the acoustic one, such as lightness, thinness, mechanical strength, fire-resistance, etc. Low frequencies are especially difficult to absorb with conventional materials, as the order of magnitude of the wavelength is much greater than the reasonable thickness of trim panels. Therefore, a new research field has emerged to study acoustic metamaterials (AMM).

 

Aircraft noise is due to the combination of different sources such as powerful propulsion systems, high-speed aerodynamic flow over vehicle surfaces and operation of on-board systems, as air conditioners, pressurization system, etc. In order to evaluate noise levels and vibration transfer paths in the whole frequency range, there are various methods to consider, because none of them has shown a complete reliability, but can be used only in a limited frequency region. In the low frequency range, the behavior of a structure is deterministic and the basic tool applied for the analysis of vibration problems is the finite element analysis on the numerical side [101].

 

The Finite Element Method (FEM) is well-established and yields accurate results for the structural analysis of any geometrical shapes. However, the metamaterials require a mesh of all the details of the constituent unit cells, so this method can become very costly in computational time when large components are analyzed. Efficient FEM models have been recently implemented on the basis of Carrera Unified Formulation (CUF) to perform the vibro-acoustic analysis of advanced materials coupled with fluid [2] and the dynamic characterization of composite metamaterials [3].

 

Applying these innovative models, the present work aims to analyze the transmission loss properties of sandwich structures with metamaterial core. The metamaterial configurations considered are inspired to the work [4]. The results demonstrate that a new concept of sandwich light-weight structures can be conceived by taking into account the acoustic requirement in the design of aerospace trim panels. 

References

[1] N. Viken, Chris K. Koukounian, Mechefske, ‘Computational modelling and experimental verification of       the vibro-acoustic behavior of aircraft fuselage sections’, Applied Acoustics, 132, 8-18, 2018.

[2] M. Cinefra, M.C. Moruzzi, S. Bagassi, E. Zappino, E. Carrera, ‘Vibro-acoustic analysis of composite plate-cavity systems via CUF finite elements’, Composite Structures, 259, 113428, 2020.

[3] A. Garcia De Miguel, M. Cinefra, M. Filippi, A. Pagani, E. Carrera, ‘Validation of FEM models based on Carrera Unified Formulation for the parametric characterization of composite metamaterials’, Journal of Sound and Vibration, 498, 115979, 2021.

[4] X. Zhang, X. Huang, G. Lu, ‘Tunable bandgaps and acoustic characteristics of perforated Miura-ori phononic structures’, International Journal of Mechanical Sciences, 253, 108389, 2023.

Presenting Author: Maria Cinefra Politecnico di Bari

Presenting Author Biography: Since 2019 Maria Cinefra is Associate Professore at the Department of Mechanics, Mathematics and Management of Politecnico di Bari. From July 2015 to November 2019, she was Associate Professor at the Department of Mechanics and Aerospace Engineering of Politecnico di Torino.
After earning two degrees (Bachlor, March 2007, and Master, December 2008) at the Politecnico di Torino in Aerospace Engineering, she was enrolled in a Ph.D. (from January 2009 to April 2012) under the supervision of Prof. Carrera at Politecnico di Torino and a foreign co-advisor, Prof. Olivier Polit at the University of Paris Ouest Nanterre. Her PhD research project, related to the ’Thermo-mechanical design of multi-layered plates and shell embedding FGM layers’, was funded by the Fonds National de la Recherche of Luxembourg and it was performed in collaboration with the CRP Henri Tudor of Esch (Lux). She was awarded for the best Ph.D paper (Ian Marshall’s Award) at the 16th International Conference on Composite Structures (28-30 June 2011, Porto, Portugal).

Since 2010, she holds teaching activity in different courses at Bachelor and Master levels: ‘Fundamentals of Structural Mechanics’, ‘Aeronautic Legislation, human factors and safety’, ’Non-linear analysis of structures’, ’Structures for spatial vehicles’, ‘Aeroelasticity’ and ‘Aeronautical Constructions’.

Her research topics cover: composite materials, metamaterials, shell finite elements, meshless methods, smart structures, functionally graded materials, thermal stress analysis, multifield interaction, vibro-acoustic analysis, panel flutter, advanced kinematic theories for plates and shells, mixed variational methods, local-global methods, failure analysis of laminated structures.

M. Cinefra is author and coauthor of more than 100 papers on the above topics, most of which have been published in first rate international journals, as well as a book published by J Wiley & Sons with the title ‘Finite Element Analysis of Structures through Unified Formulation’. Cinefra’s papers have had about 5000 citations with h-index=38 (data taken from Scopus).

Authors:

Maria Cinefra Politecnico di Bari
Martino Carlo Moruzzi Università di Bologna
Giuseppe Petrone Università degli Studi di Napoli Federico II
Marco Petrolo Politecnico di Torino