{"id":71576,"date":"2024-11-26T10:19:14","date_gmt":"2024-11-26T08:19:14","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=71576"},"modified":"2024-11-26T11:47:01","modified_gmt":"2024-11-26T09:47:01","slug":"these-maha-karam","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/a-la-une\/these-maha-karam.html","title":{"rendered":"Maha KARAM's thesis: \"Contribution to Non-Destructive Testing of structures by Laser Ultrasonics. Optimization of non-contact surface waves generation\" on 26\/11 14h00"},"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_10du47ga5g7yy\" 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-71576'><div class='entry-content-wrapper clearfix'>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-k5dohoxw-49382229f6110f77b592f8bbcf6ee126\">\n#top .av-special-heading.av-k5dohoxw-49382229f6110f77b592f8bbcf6ee126{\nmargin:0 0 10px 0;\npadding-bottom:4px;\n}\nbody .av-special-heading.av-k5dohoxw-49382229f6110f77b592f8bbcf6ee126 .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-k5dohoxw-49382229f6110f77b592f8bbcf6ee126 .av-subheading{\nfont-size:15px;\n}\n<\/style>\n<div  class='av-special-heading av-k5dohoxw-49382229f6110f77b592f8bbcf6ee126 av-special-heading-h4  avia-builder-el-1  el_after_av_layerslider  el_before_av_hr  avia-builder-el-first  av-linked-heading'><h4 class='av-special-heading-tag'  itemprop=\"headline\"  >Thesis Maha KARAM : \" Contribution to Non-Destructive Testing of structures by Laser Ultrasonics. Optimization of non-contact surface wave\" on 26\/11 14h<\/h4><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-fd5f2e9d63bf552d6910d12f255eb26e'   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>Thesis Maha KARAM<br \/>\n<\/strong><\/p>\n<p>Defence: 26 November 14:00<strong><br \/>\n<\/strong>IEMN Amphitheatre<\/p>\n<\/div><\/section>\n\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-jtefqx33-6db969b2e204313ebd62331ed4fc69ec\">\n#top .av_textblock_section.av-jtefqx33-6db969b2e204313ebd62331ed4fc69ec .avia_textblock{\nfont-size:15px;\n}\n<\/style>\n<section  class='av_textblock_section av-jtefqx33-6db969b2e204313ebd62331ed4fc69ec'   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><strong><span style=\"color: #800000;\">Jury<\/span><\/strong><i><\/i><\/h5>\n<table>\n<tbody>\n<tr>\n<td><strong>Fr\u00e9d\u00e9ric JENOT<\/strong><\/td>\n<td><\/td>\n<td>University Professor<\/td>\n<td><\/td>\n<td>Polytechnic University of Hauts-de-France<\/td>\n<td><\/td>\n<td>Thesis Co-Director<\/td>\n<\/tr>\n<tr>\n<td>Mounsif ECH-CHERIF EL-KETTANI<\/td>\n<td><\/td>\n<td>University Professor<\/td>\n<td><\/td>\n<td>Laboratoire Ondes et Milieux Complexes, LOMC UMR 6294, UNIVERSITE DU HAVRE<\/td>\n<td><\/td>\n<td>Rapporteur<\/td>\n<\/tr>\n<tr>\n<td>Martin ROBIN<\/td>\n<td><\/td>\n<td>Senior lecturer<\/td>\n<td><\/td>\n<td>Process and Materials Sciences Laboratory - UPR 3407<\/td>\n<td><\/td>\n<td>Examinateur<\/td>\n<\/tr>\n<tr>\n<td>Rabih TAUK<\/td>\n<td><\/td>\n<td>Professor<\/td>\n<td><\/td>\n<td>Lebanese University Research Platform in Nanotechnology Sciences<\/td>\n<td><\/td>\n<td>Thesis Co-Director<\/td>\n<\/tr>\n<tr>\n<td>Meriem CHRIFI ALAOUI<\/td>\n<td><\/td>\n<td>Senior lecturer<\/td>\n<td><\/td>\n<td>Polytechnic University of Hauts-de-France<\/td>\n<td><\/td>\n<td>Co-encadrant de th\u00e8se<\/td>\n<\/tr>\n<tr>\n<td>Jihan JABBOUR<\/td>\n<td><\/td>\n<td>Professor<\/td>\n<td><\/td>\n<td>Lebanese University Research Platform in Nanotechnology Sciences<\/td>\n<td><\/td>\n<td>Co-encadrant de th\u00e8se<\/td>\n<\/tr>\n<tr>\n<td>Elias RACHID<\/td>\n<td><\/td>\n<td>Professor<\/td>\n<td><\/td>\n<td>Saint-Joseph University of Beirut<\/td>\n<td><\/td>\n<td>Rapporteur<\/td>\n<\/tr>\n<tr>\n<td>Wehbe FARAH<\/td>\n<td><\/td>\n<td>Professor<\/td>\n<td><\/td>\n<td>Saint-Joseph University of Beirut-Faculty of Sciences<\/td>\n<td><\/td>\n<td>Examinateur<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h5><strong><span style=\"color: #800000;\">\u00a0<\/span><\/strong><\/h5>\n<h5>Summary:<\/h5>\n<p>The Ultrasound-Laser method is an important and interesting approach for non-contact non-destructive testing (NDT) of structures. The aim of this thesis is to optimise this method to improve the detection and characterisation of defects using surface acoustic waves, by modifying the shape of the thermoelastic source via that of the generating laser beam. We presented the main characteristics of Rayleigh wave propagation in a homogeneous and isotropic medium and developed a numerical model based on the finite element method to simulate the generation of ultrasonic waves by two separate linear source arrays. This model was also used to analyse the wave-defect interaction in different configurations. Experimentally, the shape of the laser source was modified using various optical devices. Different arrays of thermoelastic sources were studied in terms of excited Rayleigh waves and their interactions with various open defects in an aluminium sample. In particular, we have shown that it is possible to easily and simultaneously excite quasi-monochromatic and pulsed Rayleigh waves. This makes it possible to improve the detection and characterisation of defects using the frequency spectra thus obtained. Various artificial defects were considered and the analysis of the propagation of Rayleigh waves reflected and transmitted by these defects highlighted the interest of the optical devices studied. The results obtained from the different experimental configurations clearly demonstrated the advantages of each of them for the NDT of the structure concerned.<\/p>\n<p align=\"justify\"><strong>Abstract:<\/strong><\/p>\n<p>Laser Ultrasonics method is an important and interesting approach to non-contact Non-Destructive Testing of structures. The aim of this thesis is to optimize this method for improving the detection and characterization of defects using surface acoustic waves, by modifying the shape of the thermoelastic source via that of the generating laser beam. We have presented the main characteristics of Rayleigh waves propagation in a homogeneous and isotropic medium, and developed a numerical model based on the finite element method to simulate the generation of ultrasonic waves by two distinct arrays of line sources. The model was also used to analyse waves-defects interaction in different configurations. Experimentally, the shape of the laser source was modified using various optical devices. Different arrays of thermoelastic sources were studied in terms of excited Rayleigh waves and their interactions with various open defects in an aluminium sample. In particular, we have shown that quasi-monochromatic and pulsed Rayleigh waves can be excited easily and simultaneously. This makes it possible to improve defect detection and characterization with regard to the frequency spectra thus obtained. Various artificial defects have been considered and the analysis of the propagation of Rayleigh waves reflected and transmitted by these defects has demonstrated the interest of the optical devices studied. The results obtained from the various experimental configurations clearly demonstrated the benefits of each for the NDT of the structure concerned.<\/p>\n<\/div><\/section>","protected":false},"excerpt":{"rendered":"","protected":false},"author":20,"featured_media":71447,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,8,319,65,87,84],"tags":[],"class_list":["post-71576","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-a-la-une","category-actualites","category-actualites2022","category-agenda","category-agenda-en","category-agenda-en-en"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/71576","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=71576"}],"version-history":[{"count":0,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/71576\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media\/71447"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=71576"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=71576"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=71576"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}