{"id":55710,"date":"2022-12-13T16:03:13","date_gmt":"2022-12-13T14:03:13","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=55710"},"modified":"2022-12-13T16:03:31","modified_gmt":"2022-12-13T14:03:31","slug":"these-a-terroir-etude-et-realisation-de-metamateriaux-acoustiques-architectures","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/theses-2022\/these-a-terroir-etude-et-realisation-de-metamateriaux-acoustiques-architectures.html","title":{"rendered":"THESIS: A. TERROIR - Study and production of architectural acoustic metamaterials"},"content":{"rendered":"<div id='layer_slider_1'  class='avia-layerslider main_color avia-shadow  avia-builder-el-0  el_before_av_heading  avia-builder-el-first  container_wrap sidebar_right'  style='height: 261px;'  ><div id=\"layerslider_58_ripouhu8hbhb\" data-ls-slug=\"homepageslider\" class=\"ls-wp-container fitvidsignore ls-selectable\" style=\"width:1140px;height:260px;margin:0 auto;margin-bottom: 0px;\"><div class=\"ls-slide\" data-ls=\"duration:6000;transition2d:5;\"><img loading=\"lazy\" decoding=\"async\" width=\"2600\" height=\"270\" src=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1.jpg\" class=\"ls-bg\" alt=\"\" srcset=\"https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1.jpg 2600w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1-300x31.jpg 300w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1-768x80.jpg 768w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1-1030x107.jpg 1030w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1-1500x156.jpg 1500w, https:\/\/www.iemn.fr\/wp-content\/uploads\/2019\/01\/sliders_news1-705x73.jpg 705w\" sizes=\"auto, (max-width: 2600px) 100vw, 2600px\" \/><ls-layer style=\"font-size:14px;text-align:left;font-style:normal;text-decoration:none;text-transform:none;font-weight:700;letter-spacing:0px;border-style:solid;border-color:#000;background-position:0% 0%;background-repeat:no-repeat;width:180px;height:30px;left:0px;top:231px;line-height:32px;color:#ffffff;border-radius:6px 6px 6px 6px;padding-left:50px;background-color:rgba(0, 0, 0, 0.57);\" class=\"ls-l ls-ib-icon ls-text-layer\" data-ls=\"minfontsize:0;minmobilefontsize:0;\"><i class=\"fa fa-quote-right\" style=\"color:#ffffff;margin-right:0.8em;font-size:1em;transform:translateY( -0.125em );\"><\/i>ACTUALITES<\/ls-layer><\/div><\/div><\/div><div id='after_layer_slider_1'  class='main_color av_default_container_wrap container_wrap sidebar_right'  ><div class='container av-section-cont-open' ><div class='template-page content  av-content-small alpha units'><div class='post-entry post-entry-type-page post-entry-55710'><div class='entry-content-wrapper clearfix'>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-lbmalr54-ea26631ef133599fdd06e83687bbf37c\">\n#top .av-special-heading.av-lbmalr54-ea26631ef133599fdd06e83687bbf37c{\nmargin:0 0 10px 0;\npadding-bottom:4px;\n}\nbody .av-special-heading.av-lbmalr54-ea26631ef133599fdd06e83687bbf37c .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-lbmalr54-ea26631ef133599fdd06e83687bbf37c .av-subheading{\nfont-size:15px;\n}\n<\/style>\n<div  class='av-special-heading av-lbmalr54-ea26631ef133599fdd06e83687bbf37c av-special-heading-h2  avia-builder-el-1  el_after_av_layerslider  el_before_av_hr  avia-builder-el-first'><h2 class='av-special-heading-tag'  itemprop=\"headline\"  >THESIS: A. TERROIR - Study and production of architectural acoustic metamaterials <\/h2><div class=\"special-heading-border\"><div class=\"special-heading-inner-border\"><\/div><\/div><\/div>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-18u73nj-dad6a947580930e400fc42ba200e80f1\">\n#top .hr.av-18u73nj-dad6a947580930e400fc42ba200e80f1{\nmargin-top:5px;\nmargin-bottom:5px;\n}\n.hr.av-18u73nj-dad6a947580930e400fc42ba200e80f1 .hr-inner{\nwidth:100%;\n}\n<\/style>\n<div  class='hr av-18u73nj-dad6a947580930e400fc42ba200e80f1 hr-custom  avia-builder-el-2  el_after_av_heading  el_before_av_textblock  hr-left hr-icon-no'><span class='hr-inner inner-border-av-border-thin'><span class=\"hr-inner-style\"><\/span><\/span><\/div>\n<section  class='av_textblock_section av-jriy64i8-2f4600354c0449b610997916bbd9b6bc'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" >\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-13ewzjw-68e036126b913e5028f77311dc66b825\">\n.av_font_icon.av-13ewzjw-68e036126b913e5028f77311dc66b825{\ncolor:#bfbfbf;\nborder-color:#bfbfbf;\n}\n.av_font_icon.av-13ewzjw-68e036126b913e5028f77311dc66b825 .av-icon-char{\nfont-size:60px;\nline-height:60px;\n}\n<\/style>\n<span  class='av_font_icon av-13ewzjw-68e036126b913e5028f77311dc66b825 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='\ue8c9' data-av_iconfont='entypo-fontello' ><\/span><\/span>\n<p><strong>A. LAND<br \/>\n<\/strong><\/p>\n<p>Final exam: 25 March 2022<strong><br \/>\n<\/strong>Th\u00e8se de doctorat en Acoustique, Universit\u00e9 de Lille, ENGSYS Sciences de l\u2019ing\u00e9nierie et des syst\u00e8mes,<\/p>\n<\/div><\/section>\n<section  class='av_textblock_section av-jtefqx33-628129dba2299b2ecd65ebfc92eac29d'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><div  class='hr av-kjh3zw-4dff888f744b728a1aca9b3a0971493a hr-default  avia-builder-el-6  avia-builder-el-no-sibling'><span class='hr-inner'><span class=\"hr-inner-style\"><\/span><\/span><\/div>\n<h5>Summary:<\/h5>\n<p>In the field of underwater acoustics, the detection of vessels is now a widely studied subject. Hull coatings can be used to avoid detection, but their performance needs to be improved to keep pace with the development of SONAR systems, particularly at low frequencies. Metamaterials are used for this purpose because of their frequency filtering and local resonance properties. However, another strategy is to look at metamaterials with unusual mechanical properties, such as an anti-auxetic Poisson's ratio, i.e. greater than 0.5. In this thesis, a structure making it possible to obtain such Poisson's ratios is studied, in the case of infinite volumes and then adapted to the case of plates of finite thickness, using numerical tools based on finite element simulation. A homogenisation method in the long wavelength limit is developed from the numerical tools by exploiting the dispersion curves and is used to obtain the effective properties of the structure both in volume and in plate. In the case of the plate, the model is adapted to take into account a matrix density. The plate structure is then characterised statically by tensile tests and dynamically by the identification of bending modes. These tests highlight the limits of validity of the homogenisation model. Finally, coatings are designed on the basis of the architectural structure to meet the performance targets set, particularly at low frequencies, for underwater stealth. Several panels are then proposed.<\/p>\n<h5>Abstract:<\/h5>\n<p>In the context of underwater acoustics, the detection of vessels is now a widely studied subject. Hull coatings allow to avoid this detection but it is necessary to improve their performances to follow the development of SONAR systems, in particular for low frequencies. Metamaterials are used for this purpose for their frequency filtering and local resonance properties. However, another strategy is to focus on metamaterials with unusual mechanical properties, such as an anti-auxium Poisson's ratio, i.e. greater than 0.5. In this thesis, a structure allowing to obtain such Poisson's ratio is studied, in the case of infinite volumes and then adapted to the case of plates of finite thickness, by numerical tools based on finite element simulation. A homogenization method in the long wavelength limit is developed from the numerical tools by exploiting the dispersion curves and is used to obtain the effective properties of the structure both in volume and in plate. In the case of the plate, the model is adapted to take into account a matrix density. The plate structure is then characterized statically by tensile tests and dynamically by the identification of bending modes. These tests allow to highlight the limits of validity of the homogenization model. Finally, coatings are designed from the architectural structure to meet the performance objectives set, especially in low frequencies, for underwater stealth. Several panels are then proposed.<\/p>\n<\/div><\/section>","protected":false},"excerpt":{"rendered":"","protected":false},"author":20,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[316],"tags":[],"class_list":["post-55710","post","type-post","status-publish","format-standard","hentry","category-theses-2022"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/55710","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\/20"}],"replies":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/comments?post=55710"}],"version-history":[{"count":0,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/55710\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=55710"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=55710"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=55710"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}