Vibrant Times for Mechanical Metamaterials
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Arxiv:1612.05988V1 [Cond-Mat.Soft] 18 Dec 2016
Bistable Auxetic Mechanical Metamaterials Inspired by Ancient Geometric Motifs Ahmad Rafsanjania,b, Damiano Pasinib,∗ aHarvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA bMechanical Engineering Department, McGill University, 817 Sherbrooke Street West, Montr´eal,Qu´ebec H3A OC3, Canada Abstract Auxetic materials become thicker rather than thinner when stretched, exhibiting an unusual negative Poisson’s ratio well suited for designing shape transforming metama- terials. Current auxetic designs, however, are often monostable and cannot maintain the transformed shape upon load removal. Here, inspired by ancient geometric motifs arranged in square and triangular grids, we introduce a class of switchable architec- tured materials exhibiting simultaneous auxeticity and structural bistability. The ma- terial concept is experimentally realized by perforating various cut motifs into a sheet of rubber, thus creating a network of rotating units connected with compliant hinges. The metamaterial performance is assessed through mechanical testing and accurately predicted by a coherent set of finite element simulations. A discussion on a rich set of mechanical phenomena follows to shed light on the main design principles governing bistable auxetics. Keywords: mechanical metamaterials, auxetics, instability arXiv:1612.05988v1 [cond-mat.soft] 18 Dec 2016 ∗corresponding author Email addresses: [email protected] (Ahmad Rafsanjani), [email protected] (Damiano Pasini) Preprint submitted to Elsevier December 20, 2016 1. Introduction Mechanical metamaterials are designer matter with exotic mechanical properties mainly controlled by their unique architecture rather than their chemical make-up [1]. The Poisson’s ratio, ν, is the ratio between the transverse strain, "t, and the longitudinal strain, "l, in the loading direction (ν = −"t="l). -
Vibrant Times for Mechanical Metamaterials
Downloaded from orbit.dtu.dk on: Dec 24, 2018 Vibrant times for mechanical metamaterials Christensen, Johan; Kadic, Muamer; Kraft, Oliver; Wegener, Martin Published in: M R S Communications Link to article, DOI: 10.1557/mrc.2015.51 Publication date: 2015 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Christensen, J., Kadic, M., Kraft, O., & Wegener, M. (2015). Vibrant times for mechanical metamaterials. M R S Communications, 5(3), 453-462. DOI: 10.1557/mrc.2015.51 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. MRS Communications (2015), 1 of 10 © Materials Research Society, 2015. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. -
Auxetic-Like Metamaterials As Novel Earthquake Protections
AUXETIC-LIKE METAMATERIALS AS NOVEL EARTHQUAKE PROTECTIONS Bogdan Ungureanu1,2*, Younes Achaoui2*, Stefan Enoch2, Stéphane Brûlé3, Sébastien Guenneau2 1 Faculty of Civil Engineering and Building Services Technical University “Gheorghe Asachi” of Iasi, 43, Dimitrie Mangeron Blvd., Iasi 700050, Romania, 2 Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR7249, 13013 Marseille, France, 3 Dynamic Soil Laboratory, Ménard, 91620 Nozay, France. Email: [email protected] ; [email protected] *Equal contributing authors Abstract. We propose that wave propagation through a class of mechanical metamaterials opens unprecedented avenues in seismic wave protection based on spectral properties of auxetic-like metamaterials. The elastic parameters of these metamaterials like the bulk and shear moduli, the mass density, and even the Poisson ratio, can exhibit negative values in elastic stop bands. We show here that the propagation of seismic waves with frequencies ranging from 1Hz to 40Hz can be influenced by a decameter scale version of auxetic-like metamaterials buried in the soil, with the combined effects of impedance mismatch, local resonances and Bragg stop bands. More precisely, we numerically examine and illustrate the markedly different behaviors between the propagation of seismic waves through a homogeneous isotropic elastic medium (concrete) and an auxetic-like metamaterial plate consisting of 43 cells (40mx40mx40m), utilized here as a foundation of a building one would like to protect from seismic site effects. This novel class of seismic metamaterials opens band gaps at frequencies compatible with seismic waves when they are designed appropriately, what makes them interesting candidates for seismic isolation structures. Keywords: stop bands, auxetics, mechanical metamaterials, seismic waves. -
Idealized 3D Auxetic Mechanical Metamaterial: an Analytical, Numerical, and Experimental Study
materials Article Idealized 3D Auxetic Mechanical Metamaterial: An Analytical, Numerical, and Experimental Study Naeim Ghavidelnia 1 , Mahdi Bodaghi 2 and Reza Hedayati 3,* 1 Department of Mechanical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave, Tehran 1591634311, Iran; [email protected] 2 Department of Engineering, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK; [email protected] 3 Novel Aerospace Materials, Faculty of Aerospace Engineering, Delft University of Technology (TU Delft), Kluyverweg 1, 2629 HS Delft, The Netherlands * Correspondence: [email protected] or [email protected] Abstract: Mechanical metamaterials are man-made rationally-designed structures that present un- precedented mechanical properties not found in nature. One of the most well-known mechanical metamaterials is auxetics, which demonstrates negative Poisson’s ratio (NPR) behavior that is very beneficial in several industrial applications. In this study, a specific type of auxetic metamaterial structure namely idealized 3D re-entrant structure is studied analytically, numerically, and experi- mentally. The noted structure is constructed of three types of struts—one loaded purely axially and two loaded simultaneously flexurally and axially, which are inclined and are spatially defined by angles q and j. Analytical relationships for elastic modulus, yield stress, and Poisson’s ratio of the 3D re-entrant unit cell are derived based on two well-known beam theories namely Euler–Bernoulli and Timoshenko. Moreover, two finite element approaches one based on beam elements and one based on volumetric elements are implemented. Furthermore, several specimens are additively Citation: Ghavidelnia, N.; Bodaghi, manufactured (3D printed) and tested under compression. -
Bistable Auxetic Mechanical Metamaterials Inspired by Ancient Geometric Motifs
Extreme Mechanics Letters 9 (2016) 291–296 Contents lists available at ScienceDirect Extreme Mechanics Letters journal homepage: www.elsevier.com/locate/eml Bistable auxetic mechanical metamaterials inspired by ancient geometric motifs Ahmad Rafsanjani a,b, Damiano Pasini b,∗ a John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, USA b Mechanical Engineering Department, McGill University, 817 Sherbrooke Street West, Montréal, Québec H3A OC3, Canada graphical abstract article info a b s t r a c t Article history: Auxetic materials become thicker rather than thinner when stretched, exhibiting an unusual negative Received 6 June 2016 Poisson's ratio well suited for designing shape transforming metamaterials. Current auxetic designs, Received in revised form however, are often monostable and cannot maintain the transformed shape upon load removal. Here, 18 July 2016 inspired by ancient geometric motifs arranged in square and triangular grids, we introduce a class Accepted 6 September 2016 of switchable architected materials exhibiting simultaneous auxeticity and structural bistability. The Available online 23 September 2016 material concept is experimentally realized by perforating various cut motifs into a sheet of rubber, thus creating a network of rotating units connected with compliant hinges. The metamaterial performance Keywords: Mechanical metamaterials is assessed through mechanical testing and accurately predicted by a coherent set of finite element Auxetics simulations. A discussion on a rich set of mechanical phenomena follows to shed light on the main design Snap-through Instability principles governing bistable auxetics. ' 2016 Elsevier Ltd. All rights reserved. 1. Introduction the ratio between the transverse strain, "t , and the longitudinal strain, "l, in the loading direction (ν D −"t ="l). -
Computational Modelling of Auxetics
COMPUTATIONAL MODELLING OF AUXETICS TOMASZ STREK Institute of Applied Mechanics Poznan University of Technology ul. Jana Pawla II 24, 60-965 Poznan, Poland Date: 2018.10.11 1 NEGATIVE POISSON’S RATIO Materials with negative Poisson’s ratio (NPR), at present, often referred to as auxetics [Evans, 1991], have been known for years. The key to this auxetic behavior is the negative Poisson’s ratio [Love, 1892]. It is well known that the range of the Poisson's ratio for the 3D isotropic material is from -1 to 0.5, while for 2D structures this range is from -1 to 1. In the early 1900s, a German physicist Woldemar Voigt [1928] was the first who reported this property and his work suggested that the crystals somehow become thicker laterally when stretched longitudinally nevertheless it was ignored for decades. Typically, Poisson’s ratio of isotropic materials is positive, what means that common materials shrink transversely when stretched. An auxetic material behaves differently, i.e. if it is stretched in one direction, it expands along (at least one of) the transverse directions. Poisson’s ratio is within the range 1 1 (d 1) . 3D isotropic systems can exhibit Poisson’s ratios within the range 1 0.5. For anisotropic materials Poisson’s ratio can have any positive or negative values in certain directions. 2 EFFECTIVE POISSON RATIO Effective Poisson’s ratio as the negative ratio of the an average transverse to average longitudinal strain transverse eff . longitudinal Effective Young’s modulus as the ratio of an average longitudinal stress to average longitudinal strain longitudinal Eeff . -
Auxetic-Like Metamaterials As Novel Earthquake Protections Bogdan Ungureanu, Younes Achaoui, Stefan Enoch, Stéphane Brulé, Sébastien Guenneau
Auxetic-like metamaterials as novel earthquake protections Bogdan Ungureanu, Younes Achaoui, Stefan Enoch, Stéphane Brulé, Sébastien Guenneau To cite this version: Bogdan Ungureanu, Younes Achaoui, Stefan Enoch, Stéphane Brulé, Sébastien Guenneau. Auxetic- like metamaterials as novel earthquake protections. EPJ Applied Metamaterials, EDP Sciences, 2016, 2, pp.17. 10.1051/epjam/2016001. hal-01283651 HAL Id: hal-01283651 https://hal.archives-ouvertes.fr/hal-01283651 Submitted on 8 Nov 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Auxetic-like metamaterials as novel earthquake protections Bogdan Ungureanu1,2,a, Younes Achaoui2,a, Stefan Enoch2, Stéphane Brûlé3, and Sébastien Guenneau2,* 1 Faculty of Civil Engineering and Building Services Technical University ‘‘Gheorghe Asachi’’ of Iasi, 43, Dimitrie Mangeron Blvd., 700050 Iasi, Romania 2 Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR7249, 13013 Marseille, France 3 Dynamic Soil Laboratory, Ménard, 91620 Nozay, France Abstract – We propose that wave propagation through a class of mechanical metamaterials opens unprecedented avenues in seismic wave protection based on spectral properties of auxetic-like metamaterials. The elastic parameters of these metamaterials like the bulk and shear moduli, the mass density, and even the Poisson ratio, can exhibit neg- ative values in elastic stop bands. -
Acoustic Metamaterial Properties of a 2D Closed Cellular Solid with Entrained Fluid
Acoustic metamaterial properties of a 2D closed cellular solid with entrained fluid THÈSE NO 7026 (2016) PRÉSENTÉE LE 20 MAI 2016 À LA FACULTÉ DES SCIENCES ET TECHNIQUES DE L'INGÉNIEUR LABORATOIRE DE MODÉLISATION MÉCANIQUE MULTI-ÉCHELLE PROGRAMME DOCTORAL EN MÉCANIQUE ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR Vladimir DORODNITSYN acceptée sur proposition du jury: Prof. F. Gallaire, président du jury Prof. W. Curtin, Dr B. Van Damme, directeurs de thèse Prof. K. Van Den Abeele, rapporteur Dr A. Bergamini, rapporteur Dr H. Lissek, rapporteur Suisse 2016 Abstract Metamaterials are often defined as artificial compositions designed to exhibit desired physical properties. These materials attract a lot of research attention due to unusual behavior that may not yet have been seen in nature. Although there is no commonly accepted definition for metamaterials, they are typically associated with peculiar macroscale properties resulting from their substructure. The electromagnetic metamaterial concept was first developed in 1968. As the wave theory is similar in every field, the achievements in optics were reflected in acoustics several decades later. This allowed developing acoustic metamaterials with such extraordinary properties as negative refractive index, negative bulk modulus and mass density, acoustic lensing, sound wave spectral decomposition, and acoustic bandgaps. All of those features are not only attractive scientifically, but are of interest for plenty of potential applications, including sound and vibration insulation, waveguiding, audible and high-frequency filtering, and even seismic absorption. On the other hand, cellular solids and saturated porous media have been studied for a long time. These media are abundant in nature as granular soils, wood, rocks, bones, and foams. -
Vibrant Times for Mechanical Metamaterials
Downloaded from orbit.dtu.dk on: Sep 30, 2021 Vibrant times for mechanical metamaterials Christensen, Johan; Kadic, Muamer; Kraft, Oliver; Wegener, Martin Published in: M R S Communications Link to article, DOI: 10.1557/mrc.2015.51 Publication date: 2015 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Christensen, J., Kadic, M., Kraft, O., & Wegener, M. (2015). Vibrant times for mechanical metamaterials. M R S Communications, 5(3), 453-462. https://doi.org/10.1557/mrc.2015.51 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. MRS Communications (2015), 1 of 10 © Materials Research Society, 2015. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. -
Vibrant Times for Mechanical Metamaterials
Downloaded from orbit.dtu.dk on: Sep 26, 2021 Vibrant times for mechanical metamaterials Christensen, Johan; Kadic, Muamer; Kraft, Oliver; Wegener, Martin Published in: M R S Communications Link to article, DOI: 10.1557/mrc.2015.51 Publication date: 2015 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Christensen, J., Kadic, M., Kraft, O., & Wegener, M. (2015). Vibrant times for mechanical metamaterials. M R S Communications, 5(3), 453-462. https://doi.org/10.1557/mrc.2015.51 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. MRS Communications (2015), 1 of 10 © Materials Research Society, 2015. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. -
Auxetic Mechanical Metamaterial Based Stretchable Electronics
This document is downloaded from DR‑NTU (https://dr.ntu.edu.sg) Nanyang Technological University, Singapore. Auxetic mechanical metamaterial based stretchable electronics Jiang, Ying 2019 Jiang, Y. (2019). Auxetic mechanical metamaterial based stretchable electronics. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/136917 https://doi.org/10.32657/10356/136917 This work is licensed under a Creative Commons Attribution‑NonCommercial 4.0 International License (CC BY‑NC 4.0). Downloaded on 07 Oct 2021 21:46:18 SGT AUXETIC MECHANICAL METAMATERIAL BASED STRETCHABLE ELECTRONICS JIANG YING SCHOOL OF MATERIALS SCIENCE AND ENGINEERING 2019 AUXETIC MECHANICAL METAMATERIAL BASED STRETCHABLE ELECTRONICS JIANG YING SCHOOL OF MATERIALS SCIENCE AND ENGINEERING A thesis submitted to the Nanyang Technological University in partial fulfilment of the requirement for the degree of Doctor of Philosophy 2019 Authorship Attribution Statement This thesis contains material from 2 papers published in the following peer-reviewed journal in which I am listed as an author. Chapter 4,5 is published as Y. Jiang, Z. Liu, N. Matsuhisa, D. Qi, W. R. Leow, H. Yang, J. Yu, G. Chen, Y. Liu, C. Wan, Z. Liu and X. Chen. Auxetic mechanical metamaterials to enhance sensitivity of stretchable strain sensors. Advanced Materials 30, 1706589 (2018). DOI: 10.1002/adma.201706589. The contributions of the co-authors are as follows: • Prof. Chen provided the initial project direction and edited the manuscript drafts. • Prof. Liu assisted in all the finite element simulation and analysis, and revised the manuscript drafts. • Specific experiment procedure, characterization including microscopy, voltage distribution simulation, microcrack model and demonstration was conducted by me. -
Politecnico Di Torino
POLITECNICO DI TORINO Corso di Laurea Magistrale in Architettura per il Progetto Sostenibile Tesi di Laurea Magistrale Applications of Auxetic Models in Climatic Adaptive Building Shells Relatori: Candidato: Fabrizio Barpi Tommaso Bonfiglio Pier Paolo Riviera Anno Accademico 2019-2020 POLITECNICO DI TORINO Corso di Laurea Magistrale in Architettura per il Progetto Sostenibile Tesi di Laurea Magistrale Applications of Auxetic Models in Climatic Adaptive Building Shells Relatori: Candidato: Fabrizio Barpi Tommaso Bonfiglio Pier Paolo Riviera Anno Accademico 2019-2020 Riconoscimenti Questa ricerca sintetizza un lavoro sviluppato in un difficile periodo di pandemia globale, che non potrebbe essere stato sviluppato senza il fondamentale supporto di molti. Ringrazio profondamente i professori Fabrizio Barpi e Pier Paolo Riviera, per i loro preziosi consigli ed aver direzionato verso la retta via nel percorso di ricerca. Ringrazio i miei fedeli amici, per avermi supportato e sopportato interminabili discorsi sul tema della tesi. Un finale ringraziamento ai miei stretti familiari, senza i quali questo intero percorso non sarebbe stato possibile. 1 Contents 2 0. Abstract / 4 1. Introduction to Auxetic Materials / 6 1.1 Auxetic Metamaterials Definition / 7 1.2. Auxetic Behavior / 8 1.3 Auxetic Scales / 11 1.4 Auxetic Models / 13 2. From Contemporary to Architectural Applications / 30 2.1 Current Auxetic Materials Applications / 31 2.2 Architectural Applications / 40 2.3 Auxetic and Biomimetics / 50 3. Design Proposition – Auxetic CABS / 54 3.1 Biomimetic Building Skins / 55 3.2 Auxetic Climatic Adaptive Building Shell design / 61 3.3 The Physical Model / 71 4. Visions / 76 5. Conclusions / 80 6. References / 84 3 Abstract The auxetic metamaterials' field of research is in constant expansion, and as engineering investigation keeps zooming with the magnifying glass on their microscopic properties, architects' points of view zoom out, leading their exploration to buildings scales.