Singh, Ravi Pratap (2020) Stochastic Analysis of Periodic Structures with Uncertainties. [Tesi di dottorato]


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Item Type: Tesi di dottorato
Resource language: English
Title: Stochastic Analysis of Periodic Structures with Uncertainties
Singh, Ravi
Date: 3 February 2020
Number of Pages: 189
Institution: Università degli Studi di Napoli Federico II
Department: Ingegneria Industriale
Dottorato: Ingegneria industriale
Ciclo di dottorato: 32
Coordinatore del Corso di dottorato:
Ichchou, MohamedUNSPECIFIED
Franco, FrancescoUNSPECIFIED
Bareille, OlivierUNSPECIFIED
Petrone, GiuseppeUNSPECIFIED
Date: 3 February 2020
Number of Pages: 189
Keywords: Periodic structures, uncertainty quantification, metamaterials, FWFEM, SWFEM
Settori scientifico-disciplinari del MIUR: Area 09 - Ingegneria industriale e dell'informazione > ING-IND/04 - Costruzioni e strutture aerospaziali
Date Deposited: 07 Feb 2020 14:47
Last Modified: 17 Nov 2021 10:50

Collection description

Structures having periodic properties or repeating patterns exhibit a peculiar feature known as band gaps. Band gaps are defined as frequency intervals for which both sound and vibration cannot propagate in the material. This feature of periodic structures offers a unique dynamic effect that can be exploited for a range of engineering applications. The design of periodic media is generally based on deterministic models without considering the effect of inherent uncertainties existing in these structures. In general, the design is aimed at controlling the mechanical waves as much as possible; however, inherent uncertainties may affect their characteristics. The uncertainties, in terms of material properties and geometrical parameters, are mostly caused by in manufacturing and assembly processes. The uncertainties play an important role in altering the wave states. To address this unavoidable actuality, the effects of uncertainties need to be considered when analyzing frequency band structures (pass and stop bands) and frequency response function. With this in mind, the presented work is intended as a contribution to the probabilistic and non-probabilistic approaches, with reduced computation time, in conjunction with the wave finite element method. The contributions of this study consist of considering uncertainties in the system to evaluate the deviation of the parameters (spectral and dynamics) and their influence on the global response (band gaps and frequency response function) of 1D and 2D periodic structures. The research contribution can be partitioned into two main parts. The first part involves the probabilistic development of a direct and explicit spectral formulation employing the first-order perturbation theory to predict the dispersion of different parameters. The second part involves non-probabilistic development, using the fuzzy set theory for the assessment of the effects of data uncertainties on the dynamics of 1D and 2D periodic structures.


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