{"title":"Dynamic homogenization of random elastodynamic metamaterials using space–time Fourier transform","authors":"Ali Heidari Shirazi , Reza Abedi , Raj Kumar Pal","doi":"10.1016/j.ijsolstr.2025.113339","DOIUrl":null,"url":null,"abstract":"<div><div>The dynamic homogenization of metamaterials with transfer matrix-based methods poses significant challenges due to an inherent branch ambiguity associated with the real part of the wavenumber. This problem is exacerbated in the presence of disorder (randomness) in cell geometry or material properties. Disorder necessitates larger domains for homogenization, which increase the range of wavenumbers with a branch ambiguity. To resolve this ambiguity, we utilize a Space–Time Fourier Transform (STFT)-based technique and extract primary parameters such as wavenumber and phase velocity, alongside secondary parameters including effective mass density, elastic modulus, and Willis-coupling terms for 1D multilayer media. A variation-based criterion is used to show that dynamic Representative Volume Element (RVE) can only be defined for the primary parameters. A sensitivity analysis is conducted to show that the coefficient of variation of secondary parameters is not only much higher than that of primary parameters, but also does not decrease by increasing the Statistical Volume Element (SVE) size. Our simulations predict the appearance of minor bandgaps induced by disorder. Phenomena such as blue-shift, widening, and merging of bandgaps are observed in random realizations. The STFT technique predicts homogenized parameters in both passbands, bandgaps, and can naturally be extended to higher dimensional metamaterials.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"315 ","pages":"Article 113339"},"PeriodicalIF":3.4000,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Solids and Structures","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0020768325001258","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
The dynamic homogenization of metamaterials with transfer matrix-based methods poses significant challenges due to an inherent branch ambiguity associated with the real part of the wavenumber. This problem is exacerbated in the presence of disorder (randomness) in cell geometry or material properties. Disorder necessitates larger domains for homogenization, which increase the range of wavenumbers with a branch ambiguity. To resolve this ambiguity, we utilize a Space–Time Fourier Transform (STFT)-based technique and extract primary parameters such as wavenumber and phase velocity, alongside secondary parameters including effective mass density, elastic modulus, and Willis-coupling terms for 1D multilayer media. A variation-based criterion is used to show that dynamic Representative Volume Element (RVE) can only be defined for the primary parameters. A sensitivity analysis is conducted to show that the coefficient of variation of secondary parameters is not only much higher than that of primary parameters, but also does not decrease by increasing the Statistical Volume Element (SVE) size. Our simulations predict the appearance of minor bandgaps induced by disorder. Phenomena such as blue-shift, widening, and merging of bandgaps are observed in random realizations. The STFT technique predicts homogenized parameters in both passbands, bandgaps, and can naturally be extended to higher dimensional metamaterials.
期刊介绍:
The International Journal of Solids and Structures has as its objective the publication and dissemination of original research in Mechanics of Solids and Structures as a field of Applied Science and Engineering. It fosters thus the exchange of ideas among workers in different parts of the world and also among workers who emphasize different aspects of the foundations and applications of the field.
Standing as it does at the cross-roads of Materials Science, Life Sciences, Mathematics, Physics and Engineering Design, the Mechanics of Solids and Structures is experiencing considerable growth as a result of recent technological advances. The Journal, by providing an international medium of communication, is encouraging this growth and is encompassing all aspects of the field from the more classical problems of structural analysis to mechanics of solids continually interacting with other media and including fracture, flow, wave propagation, heat transfer, thermal effects in solids, optimum design methods, model analysis, structural topology and numerical techniques. Interest extends to both inorganic and organic solids and structures.