{"id":61408,"date":"2023-12-08T16:41:58","date_gmt":"2023-12-08T14:41:58","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=61408"},"modified":"2024-01-16T16:59:57","modified_gmt":"2024-01-16T14:59:57","slug":"les-metamateriaux-mecaniques-et-acoustiques-et-le-concept-darchitecture-de-la-cellule-unitaire","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/newsletter\/les-metamateriaux-mecaniques-et-acoustiques-et-le-concept-darchitecture-de-la-cellule-unitaire.html","title":{"rendered":"Metamaterials (mechanical and acoustic) and the concept of unit cell architecture"},"content":{"rendered":"\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-sx3vs0-44b2a8ab14b4051c54bfc3098d7228b7\">\n.flex_column.av-sx3vs0-44b2a8ab14b4051c54bfc3098d7228b7{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-sx3vs0-44b2a8ab14b4051c54bfc3098d7228b7 av_one_full  avia-builder-el-0  el_before_av_one_half  avia-builder-el-first  first flex_column_div av-zero-column-padding  '     ><p><section  class='av_textblock_section av-lq2h9d9t-12a3a08f2f507a08a759475a77dc6679 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-62291 size-full\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux5.jpg\" alt=\"\" width=\"1000\" height=\"191\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux5.jpg 1000w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux5-300x57.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux5-768x147.jpg 768w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux5-18x3.jpg 18w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux5-705x135.jpg 705w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/p>\n<\/div><\/section><br \/>\n<section  class='av_textblock_section av-lq2gsmqj-1502b9fe0245d0adffd65f475a0b3bb2 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><h1 style=\"text-align: center;\"><span style=\"color: #097482;\">Les m\u00e9tamat\u00e9riaux (m\u00e9caniques et acoustiques)\u00a0et le concept d\u2019architecture de la cellule unitaire<\/span><\/h1>\n<\/div><\/section><br \/>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lq3g1xs9-af6de04b71109c438524db760bb6479a\">\n#top .av_textblock_section.av-lq3g1xs9-af6de04b71109c438524db760bb6479a .avia_textblock{\nfont-size:14px;\n}\n<\/style>\n<section  class='av_textblock_section av-lq3g1xs9-af6de04b71109c438524db760bb6479a '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><span style=\"color: #000000;\">Bien qu&rsquo;en m\u00e9canique et en acoustique il n&rsquo;existe pas de d\u00e9finition universellement accept\u00e9e de la notion de m\u00e9tamat\u00e9riaux, il est admis que la \u00ab g\u00e9om\u00e9trie \u00bb joue un r\u00f4le fondamental dans la d\u00e9termination de leurs propri\u00e9t\u00e9s statiques et dynamiques. Si, au d\u00e9but des ann\u00e9es 2000, les formes consid\u00e9r\u00e9es \u00e9taient plut\u00f4t canoniques (matrice avec inclusions circulaires, carr\u00e9es, etc.), au fil du temps, des g\u00e9om\u00e9tries de plus en plus complexes ont \u00e9t\u00e9 explor\u00e9es gr\u00e2ce \u00e0 l\u2019augmentation de la puissance de calcul des ordinateurs et \u00e0 l\u2019\u00e9volution des technologies de fabrication.<\/span> <span style=\"color: #097482;\"><span style=\"color: #000000;\">Dans ce contexte,<\/span> la Nature, gr\u00e2ce \u00e0 des millions d\u2019ann\u00e9es d&rsquo;\u00e9volution, est un grand ma\u00eetre de \u00ab l\u2019architecture mat\u00e9rielle \u00bb pour obtenir des propri\u00e9t\u00e9s avanc\u00e9es sp\u00e9cifiques et des g\u00e9om\u00e9tries ax\u00e9es sur des fonctionnalit\u00e9s pr\u00e9cises. En prenant inspiration des architectures hi\u00e9rarchiques ou fractales, typiques de la majorit\u00e9 des syst\u00e8mes biologiques, nous montrons qu\u2019en reproduisant cet enrichissement structural \u00e0 la m\u00e9so-\u00e9chelle des m\u00e9tamat\u00e9riaux on induit des comportements d\u2019une grande richesse, ouvrant des nouvelles perspectives de contr\u00f4le des ondes \u00e9lastiques bas\u00e9es sur l\u2019activation simultan\u00e9e de divers m\u00e9canismes d\u2019att\u00e9nuation des ondes.<\/span><\/p>\n<\/div><\/section><\/p><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-15dykqo-690853588527c9e0b6608de3de826593\">\n.flex_column.av-15dykqo-690853588527c9e0b6608de3de826593{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-15dykqo-690853588527c9e0b6608de3de826593 av_one_half  avia-builder-el-4  el_after_av_one_full  el_before_av_one_half  first flex_column_div av-zero-column-padding  column-top-margin'     ><section  class='av_textblock_section av-lq2hhk08-2b698380024dc00bff08dc43dac32f95 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><h5>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb\">\n.av_font_icon.av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb{\ncolor:#097482;\nborder-color:#097482;\n}\n.av_font_icon.av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb .av-icon-char{\nfont-size:20px;\nline-height:20px;\n}\n<\/style>\n<span  class='av_font_icon av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb avia_animate_when_visible av-icon-style- avia-icon-pos-left avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue881' data-av_iconfont='entypo-fontello' ><\/span><\/span><\/h5>\n<h4><span style=\"color: #097482;\">Les m\u00e9tamat\u00e9riaux (m\u00e9caniques et acoustiques) et le concept d\u2019architecture de la cellule unitaire<\/span><\/h4>\n<p><a href=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux4.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-62288 alignleft\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux4-300x113.jpg\" alt=\"\" width=\"300\" height=\"113\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux4-300x113.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux4-18x7.jpg 18w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/metamateriaux4.jpg 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>Bien qu&rsquo;il n&rsquo;existe pas encore de d\u00e9finition universellement accept\u00e9e de la notion de \u00ab\u00a0m\u00e9tamat\u00e9riaux m\u00e9caniques et \/ ou acoustiques\u00a0\u00bb, la communaut\u00e9 scientifique a tendance \u00e0 les identifier comme des \u00ab composites pr\u00e9sentant une architecture p\u00e9riodique ou quasi-p\u00e9riodique, con\u00e7ue pour produire une r\u00e9ponse statique ou dynamique atypique face \u00e0 des contraintes sp\u00e9cifiques \u00bb.<br \/>\nL\u2019aspect \u00ab g\u00e9om\u00e9trie \u00bb joue, donc, un r\u00f4le fondamental dans la d\u00e9termination des propri\u00e9t\u00e9s des m\u00e9tamat\u00e9riaux. Par exemple, en dynamique, \u00e0 parit\u00e9 de fraction de remplissage(1), la forme des inclusions (ou des vides) et de leur distribution dans la cellule unitaire (en forme de cercle, de carreau, de croix, etc., centr\u00e9e, dispos\u00e9e aux bords, etc.) peut mener \u00e0 l\u2019ouverture de bandes interdites (fr\u00e9quences dans lesquelles la propagation des ondes est fortement att\u00e9nu\u00e9e) ou \u00e0 des courbes \u00e0 pente n\u00e9gative dans le diagramme de dispersion, et atteindre des comportements atypiques tels que la r\u00e9fraction n\u00e9gative, la protection topologique, l\u2019absorption parfaite, etc.<\/p>\n<\/div><\/section><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-wns4tc-1db3423f7cd08c59a5a437f03f40996e\">\n.flex_column.av-wns4tc-1db3423f7cd08c59a5a437f03f40996e{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-wns4tc-1db3423f7cd08c59a5a437f03f40996e av_one_half  avia-builder-el-7  el_after_av_one_half  el_before_av_one_full  flex_column_div av-zero-column-padding  column-top-margin'     ><p>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lrggoxld-b9fda0964e2eb6a8c68b67bd72300709\">\n#top .hr.hr-invisible.av-lrggoxld-b9fda0964e2eb6a8c68b67bd72300709{\nheight:55px;\n}\n<\/style>\n<div  class='hr av-lrggoxld-b9fda0964e2eb6a8c68b67bd72300709 hr-invisible  avia-builder-el-8  el_before_av_textblock  avia-builder-el-first  av-small-hide av-mini-hide'><span class='hr-inner '><span class=\"hr-inner-style\"><\/span><\/span><\/div><br \/>\n<section  class='av_textblock_section av-lq2hhk08-2b698380024dc00bff08dc43dac32f95 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p>De la m\u00eame fa\u00e7on, quand les effets de r\u00e9sonance locale sont les principaux acteurs responsables du comportement global du m\u00e9tamat\u00e9riau, la forme (et la disposition) des r\u00e9sonateurs devient essentielle. Dans ce sens-l\u00e0, on pourrait dire que<strong><span style=\"color: #097482;\"> les m\u00e9tamat\u00e9riaux portent en eux-m\u00eames le concept d\u2019architecture.<\/span><\/strong><br \/>\nSi, au d\u00e9but des ann\u00e9es 2000, les formes consid\u00e9r\u00e9es \u00e9taient plut\u00f4t canoniques (circulaires, carr\u00e9es, etc.), des g\u00e9om\u00e9tries de plus en plus complexes ont, depuis, \u00e9t\u00e9 explor\u00e9es. Ceci a \u00e9t\u00e9 permis par (i) l\u2019augmentation de la puissance de calcul des ordinateurs, ainsi qu\u2019\u00e0 (ii) l\u2019\u00e9volution des technologies de fabrication. Par exemple, l\u2019impression 3D, qui permet d\u2019obtenir \u00e0 des prix raisonnables des formes de plus en plus complexes, ou la (photo-)lithographie, qui permet une r\u00e9solution sans pr\u00e9c\u00e9dents couvrant plusieurs \u00e9chelles de longueur, en repr\u00e9sentent deux exemples importants.<\/p>\n<p><em><span style=\"font-weight: 400;\">(1)<\/span><span style=\"font-weight: 400;\"> Rapport des volumes constituant la matrice et l&rsquo;inclusion dans une cellule unitaire.<\/span><\/em><\/p>\n<\/div><\/section><\/p><\/div>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lrgd3qxy-c5901fbe23ac602b7451221c36a0022d\">\n.flex_column.av-lrgd3qxy-c5901fbe23ac602b7451221c36a0022d{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\nbackground-color:rgba(255,255,255,0.79);\n}\n<\/style>\n<div  class='flex_column av-lrgd3qxy-c5901fbe23ac602b7451221c36a0022d av_one_full  avia-builder-el-10  el_after_av_one_half  el_before_av_one_half  first flex_column_div av-zero-column-padding  column-top-margin'     ><section  class='av_textblock_section av-lq2hhk08-2b698380024dc00bff08dc43dac32f95 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><span style=\"color: #000000;\"><span style=\"color: #008080;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-62280\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/forme6-300x287.jpg\" alt=\"\" width=\"200\" height=\"191\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/forme6-300x287.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/forme6-13x12.jpg 13w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/forme6.jpg 400w\" sizes=\"auto, (max-width: 200px) 100vw, 200px\" \/><a href=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2023\/12\/forme4.png\"><br \/>\n<\/a><\/span><\/span><\/p>\n<h5>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-qawvnx-85d2366412218a7ffab4a2f7f182f097\">\n.av_font_icon.av-qawvnx-85d2366412218a7ffab4a2f7f182f097{\ncolor:#097482;\nborder-color:#097482;\n}\n.av_font_icon.av-qawvnx-85d2366412218a7ffab4a2f7f182f097 .av-icon-char{\nfont-size:20px;\nline-height:20px;\n}\n<\/style>\n<span  class='av_font_icon av-qawvnx-85d2366412218a7ffab4a2f7f182f097 avia_animate_when_visible av-icon-style- avia-icon-pos-left avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue871' data-av_iconfont='entypo-fontello' ><\/span><\/span><\/h5>\n<p><span style=\"color: #000000;\"><span style=\"color: #008080;\">Cela a ouvert la voie \u00e0 une<\/span> <strong><span style=\"color: #008080;\">nouvelle vision du concept \u00ab d\u2019architecture\u00a0\u00bb associ\u00e9e aux m\u00e9tamat\u00e9riaux, c\u2019est-\u00e0-dire \u00ab\u00a0introduire, entre l\u2019\u00e9chelle de la microstructure du mat\u00e9riau constitutif et celle de la macrostructure, d\u2019une \u00e0 plusieurs autres \u00e9chelles d\u2019organisation de la mati\u00e8re\u00a0\u00bb.<\/span><\/strong> <span style=\"color: #008080;\">Les structures hi\u00e9rarchiques ou fractales qu\u2019on retrouve dans la majorit\u00e9 des syst\u00e8mes biologiques, et pour lesquelles la m\u00eame g\u00e9om\u00e9trie peut se r\u00e9p\u00e9ter d\u2019une fa\u00e7on \u00ab\u00a0autosimilaire\u00a0\u00bb ou \u00ab\u00a0non-autosimilaire\u00a0\u00bb sur plusieurs \u00e9chelles, en sont des clairs exemples. Ces \u00e9chelles, qualifi\u00e9es comme m\u00e9soscopiques peuvent \u00eatre faiblement s\u00e9par\u00e9es (coupl\u00e9es) de l\u2019\u00e9chelle macroscopique et<\/span> <strong><span style=\"color: #008080;\">induire des comportements effectifs d\u2019une grande richesse.<\/span><\/strong><\/span><\/p>\n<\/div><\/section><\/div><\/p>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lrgd3qxy-30582e3232bd29f97162ddfd3b97cb29\">\n.flex_column.av-lrgd3qxy-30582e3232bd29f97162ddfd3b97cb29{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\nbackground-color:rgba(255,255,255,0.79);\n}\n<\/style>\n<div  class='flex_column av-lrgd3qxy-30582e3232bd29f97162ddfd3b97cb29 av_one_half  avia-builder-el-13  el_after_av_one_full  el_before_av_one_half  first flex_column_div av-zero-column-padding avia-full-stretch  column-top-margin'     ><section  class='av_textblock_section av-lq2hhk08-2b698380024dc00bff08dc43dac32f95 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><h5>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb\">\n.av_font_icon.av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb{\ncolor:#097482;\nborder-color:#097482;\n}\n.av_font_icon.av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb .av-icon-char{\nfont-size:20px;\nline-height:20px;\n}\n<\/style>\n<span  class='av_font_icon av-qawvnx-eb0fa84a59d44b41dd8d2a500ef04acb avia_animate_when_visible av-icon-style- avia-icon-pos-left avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue881' data-av_iconfont='entypo-fontello' ><\/span><\/span><\/h5>\n<h5><span style=\"color: #097482;\">La bio-inspiration\u00a0dans les m\u00e9tamat\u00e9riaux : la Nature, grand ma\u00eetre de l\u2019architecture mat\u00e9rielle<\/span><\/h5>\n<p>Si l&rsquo;humanit\u00e9 n&rsquo;a commenc\u00e9 que r\u00e9cemment \u00e0 exploiter des architectures complexes (surtout en raison de limitations technologiques),<strong> la Nature<\/strong>, gr\u00e2ce \u00e0 des millions d\u2019ann\u00e9es d&rsquo;\u00e9volution, <strong>est un grand ma\u00eetre de \u00ab\u00a0l\u2019architecture mat\u00e9rielle\u00a0\u00bb pour obtenir des propri\u00e9t\u00e9s avanc\u00e9es sp\u00e9cifiques et des g\u00e9om\u00e9tries ax\u00e9es sur des fonctionnalit\u00e9s pr\u00e9cises.<\/strong> En effet, la caract\u00e9ristique commune conduisant \u00e0 ces propri\u00e9t\u00e9s surprenantes r\u00e9side souvent dans <strong><span style=\"color: #097482;\">l\u2019organisation hi\u00e9rarchique<\/span><\/strong> de la mati\u00e8re sur plusieurs \u00e9chelles (organisation observ\u00e9e dans de nombreux mat\u00e9riaux naturels comme le bois, l&rsquo;os, les \u00e9ponges, etc.). Par cons\u00e9quent, une attention croissante a \u00e9t\u00e9 consacr\u00e9e ces derni\u00e8res ann\u00e9es \u00e0 la synth\u00e8se de mat\u00e9riaux artificiels inspir\u00e9s de la nature, mais ciblant principalement des performances quasi-statiques. A l\u2019oppos\u00e9, la prise en compte d\u2019une organisation hi\u00e9rarchique dans la conception de la cellule \u00e9l\u00e9mentaire des cristaux phononiques et des m\u00e9tamat\u00e9riaux (m\u00e9caniques et acoustiques)(2) n\u2019est que tr\u00e8s r\u00e9cente.<\/p>\n<\/div><\/section><br \/>\n<section  class='av_textblock_section av-lq2hhk08-2b698380024dc00bff08dc43dac32f95 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><em><span style=\"font-weight: 400;\">(2)<\/span><span style=\"font-weight: 400;\"> L&rsquo;architecture mat\u00e9rielle est entendue ici comme \u00ab\u00a0organisation d&rsquo;une cellule unitaire r\u00e9p\u00e9t\u00e9e sur plusieurs niveaux d&rsquo;\u00e9chelle\u00a0\u00bb.<\/span><\/em><\/p>\n<\/div><\/section><\/p><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lrgd3qxy-85885b18c34e633c36b04ef76becb25c\">\n.flex_column.av-lrgd3qxy-85885b18c34e633c36b04ef76becb25c{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\nbackground-color:rgba(255,255,255,0.79);\n}\n<\/style>\n<div  class='flex_column av-lrgd3qxy-85885b18c34e633c36b04ef76becb25c av_one_half  avia-builder-el-17  el_after_av_one_half  el_before_av_one_full  flex_column_div av-zero-column-padding avia-full-stretch  column-top-margin'     ><section  class='av_textblock_section av-lq2hhk08-2b698380024dc00bff08dc43dac32f95 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p>Dans ce contexte, nous avons pr\u00e9sent\u00e9<strong> un nouveau type de m\u00e9tamat\u00e9riau<\/strong> constitu\u00e9 d&rsquo;une matrice polym\u00e8re avec des <strong>trous en forme de croix \u00ab non autosimilaires \u00bb r\u00e9p\u00e9t\u00e9s \u00e0 plusieurs niveaux d&rsquo;\u00e9chelle<\/strong>. Cela nous a permis d\u2019atteindre un comportement hautement att\u00e9nuatif par rapport aux ondes \u00e9lastiques sur plusieurs \u00e9chelles de fr\u00e9quences gr\u00e2ce au fait que la \u00ab hi\u00e9rarchie non autosimilaire \u00bb conduit \u00e0 l\u2019ouverture de multiples (et larges) bandes interdites, y compris dans le r\u00e9gime sous-longueur d&rsquo;onde (c\u2019est \u00e0 dire quand la longueur d\u2019onde de l\u2019onde \u00e0 att\u00e9nuer est beaucoup plus grande que la taille de la structure elle-m\u00eame).<\/p>\n<p>A travers des mod\u00e8les num\u00e9riques et des mesures au vibrom\u00e8tre laser \u00e0 balayage, nous avons r\u00e9v\u00e9l\u00e9 que la hi\u00e9rarchie \u00ab\u00a0non autosimilaire\u00a0\u00bb permet l\u2019ouverture de telles bandes interdites gr\u00e2ce \u00e0 <strong>l\u2019activation simultan\u00e9e de multiples m\u00e9canismes d\u2019att\u00e9nuation<\/strong>\u00a0: diffusion de Bragg, r\u00e9sonance locale et \/ ou amplification inertielle. Ces m\u00e9canismes ont \u00e9t\u00e9 clairement identifi\u00e9s en analysant la partie imaginaire du nombre d&rsquo;onde. Cette approche de conception bas\u00e9e sur plusieurs m\u00e9canismes conduit \u00e0 des dynamiques enrichies \u00e0 diff\u00e9rentes \u00e9chelles (ouverture de bandes interdites suppl\u00e9mentaires, la conservation de celles existantes d\u00e9cal\u00e9es en fr\u00e9quence, ainsi que la possibilit\u00e9 de pr\u00e9server les m\u00e9canismes de d\u00e9formation globale des niveaux hi\u00e9rarchiques pr\u00e9c\u00e9dents, malgr\u00e9 la variation du rapport masse\/rigidit\u00e9 du syst\u00e8me global).<\/p>\n<\/div><\/section><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-wns4tc-219c562a3ab67f2abbe45e15506bd8de\">\n@keyframes av_boxShadowEffect_av-wns4tc-219c562a3ab67f2abbe45e15506bd8de-column {\n0%   { box-shadow:  0 0 0 0 #a8a8a8; opacity: 1; }\n100% { box-shadow:  0 0 10px 0 #a8a8a8; opacity: 1; }\n}\n.flex_column.av-wns4tc-219c562a3ab67f2abbe45e15506bd8de{\nbox-shadow: 0 0 10px 0 #a8a8a8;\nborder-radius:20px 20px 20px 20px;\npadding:20px 20px 20px 20px;\nbackground-color:rgba(85,160,159,0.9);\n}\n<\/style>\n<div  class='flex_column av-wns4tc-219c562a3ab67f2abbe45e15506bd8de av_one_full  avia-builder-el-19  el_after_av_one_half  el_before_av_hr  first flex_column_div shadow-not-animated  column-top-margin'     ><p>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lq2hhk08-61bfca4354f43205db21d8c8a6562023\">\n#top .av_textblock_section.av-lq2hhk08-61bfca4354f43205db21d8c8a6562023 .avia_textblock{\nfont-size:14px;\n}\n<\/style>\n<section  class='av_textblock_section av-lq2hhk08-61bfca4354f43205db21d8c8a6562023 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><span style=\"color: #ffffff;\">En conclusion, l\u2019enrichissement de l\u2019architecture des m\u00e9tamat\u00e9riaux \u00e0 la m\u00e9so-\u00e9chelle induit des comportements effectifs d\u2019une grande richesse, en offrant des nouvelles perspectives de contr\u00f4le des ondes \u00e9lastiques, favorisant l\u2019activation simultan\u00e9e de divers m\u00e9canismes d\u2019att\u00e9nuation des ondes.<\/span><\/p>\n<\/div><\/section><br \/>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lq2hhk08-c520b3bf8e403fc3ea5a322185d78c47\">\n#top .av_textblock_section.av-lq2hhk08-c520b3bf8e403fc3ea5a322185d78c47 .avia_textblock{\nfont-size:12px;\n}\n<\/style>\n<section  class='av_textblock_section av-lq2hhk08-c520b3bf8e403fc3ea5a322185d78c47 '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><p><strong><span style=\"color: #ffffff;\"> References :<\/span><\/strong><br \/>\n<span style=\"color: #ffffff;\"> <em>[1] Mazzotti, [\u2026], Miniaci. Bio-inspired non-self-similar hierarchical elastic metamaterials. International Journal of Mechanical Sciences 241:107915 (2023).<\/em><\/span><br \/>\n<span style=\"color: #ffffff;\"> <em>[2] Miniaci et al. Bio-inspired hierarchical dissipative metamaterials, Physical Review Applied, 10, 024012 (2018).<\/em><\/span><\/p>\n<\/div><\/section><\/p><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lq3rrbn6-b2fad551015528b25fb537190ccf1056\">\n#top .hr.hr-invisible.av-lq3rrbn6-b2fad551015528b25fb537190ccf1056{\nheight:20px;\n}\n<\/style>\n<div  class='hr av-lq3rrbn6-b2fad551015528b25fb537190ccf1056 hr-invisible  avia-builder-el-22  el_after_av_one_full  el_before_av_textblock '><span class='hr-inner '><span class=\"hr-inner-style\"><\/span><\/span><\/div>\n<section  class='av_textblock_section av-lq3ru9ya-f6b76a2798525607f872d4bf4739c6be '   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><div  class='avia-button-wrap av-rpqvoq-9a05bde6f0cd05381e571d282e3fe825-wrap avia-button-left  avia-builder-el-24  avia-builder-el-no-sibling '><a href='mailto:marco.miniaci@univ-lille.fr'  class='avia-button av-rpqvoq-9a05bde6f0cd05381e571d282e3fe825 av-link-btn avia-icon_select-yes-left-icon avia-size-small avia-position-left avia-color-silver'   aria-label=\"marco.miniaci@univ-lille.fr\"><span class='avia_button_icon avia_button_icon_left' aria-hidden='true' data-av_icon='\ue805' data-av_iconfont='entypo-fontello'><\/span><span class='avia_iconbox_title' >marco.miniaci@univ-lille.fr<\/span><\/a><\/div>\n<\/div><\/section>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_members_access_role":[],"_members_access_error":""},"categories":[297],"tags":[],"class_list":["post-61408","post","type-post","status-publish","format-standard","hentry","category-newsletter"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/61408","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/comments?post=61408"}],"version-history":[{"count":1,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/61408\/revisions"}],"predecessor-version":[{"id":78068,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/61408\/revisions\/78068"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=61408"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=61408"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=61408"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}