Finite element analysis of cartesian and polar phononic structures and metamaterials

Phononic structures have the “ability” to significantly attenuate wave propagation in certain frequency ranges, known as band-gaps. These structures have gained attention in the field of structural dynamics due to their property to mitigate noise and vibration harshness in several engineering domains and applications. The advent of new technological capabilities in constructing multi-scale periodic structures with local resonance phenomena has also sparked significant interest in the creation of these structures for novel metamaterials with extraordinary properties. This seminar aims to give an overview of a Finite Element approach for the numerical prediction of wave characteristics and band-gaps in cartesian and polar phononic structures. Particular attention is given to the possibility of predicting wave attenuation in polar periodic structures using the finite element analysis of unit cells:  Floquet’s theorem - the main approach to studying waveguide properties of periodic structures from the knowledge of the dynamic properties of a single period (cell), in fact, heavily relies on the translational invariance of the problem formulation and periodicity effects have been studied mainly in Cartesian coordinates while their polar counterpart has very seldom been examined. 

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Elisabetta Manconi  is associate professor at the Department of Engineering for Industrial Systems and Technologies of the University of Parma. After graduating in Mechanical Engineering, she obtained the European Doctorate in Sound and Vibration from the ISVR in Southampton in 2007 and the PhD in Industrial Engineering from the University of Parma in 2008. From 2007 to 2019 she was a researcher at the Department of Industrial Engineering of the University of Parma, carrying out research periods abroad by invitation at universities and research centres (University of Auckland; ISVR - University of Southampton, UK; UNESP - Brazil; The University of Hong Kong - Zhejiang Institute of Research and Innovation; University of Aalborg). Her main research topics are the development of numerical methods for the study of the propagation of elastic waves and the analysis of the vibro-acoustic performance of periodic and composite structures. Her work has involved studies on wave motion and dispersion phenomena, wave propagation in 2D structures, evaluation of the global loss factor of viscoelastic laminates and sandwich panels, wave characterisation of two-dimensional and axisymmetric structures both in vacuo and filled with acoustic fluid, wave propagation in helical structures, stop-bands and reflection and transmission problems. Under the guidance of Professor Brian Mace, she has contributed to developing a new technique – the wave and finite element (WFE) method – which can model the dynamic behaviour, in terms of dispersion curves and wavemodes, of large classes of waveguides.