{"id":63561,"date":"2022-05-22T15:46:28","date_gmt":"2022-05-22T20:46:28","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/piezo-ceramics-how-can-the-youngs-modulus-be-defined\/"},"modified":"2025-01-27T06:14:52","modified_gmt":"2025-01-27T11:14:52","slug":"piezo-ceramics-how-can-the-youngs-modulus-be-defined","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/piezo-ceramics-how-can-the-youngs-modulus-be-defined\/","title":{"rendered":"M\u011b\u0159en\u00ed Youngova modulu piezoelektrick\u00e9 keramiky"},"content":{"rendered":"<p>Piezokeradika jsou materi\u00e1ly, jejich\u017e mechanick\u00e9 vlastnosti jsou \u00fazce sv\u00e1z\u00e1ny s jejich elektrick\u00fdmi vlastnostmi.  Jedn\u00edm z kl\u00ed\u010dov\u00fdch parametr\u016f popisuj\u00edc\u00edch jejich mechanick\u00e9 chov\u00e1n\u00ed je Young\u016fv modul, kter\u00fd charakterizuje tuhost materi\u00e1lu.  Jeho p\u0159esn\u00e1 definice a m\u011b\u0159en\u00ed v kontextu piezokeradiky v\u0161ak vy\u017eaduje hlub\u0161\u00ed pochopen\u00ed jejich piezoelektrick\u00fdch vlastnost\u00ed.<\/p>\n<p>Definice Youngova modulu v izotropn\u00edm materi\u00e1lu<\/p>\n<p>V p\u0159\u00edpad\u011b izotropn\u00edho materi\u00e1lu, tj. materi\u00e1lu, jeho\u017e vlastnosti jsou stejn\u00e9 ve v\u0161ech sm\u011brech, je Young\u016fv modul (E) definov\u00e1n jako pom\u011br nap\u011bt\u00ed (\u03c3) a deformace (\u03b5) p\u0159i jednostrann\u00e9m tahov\u00e9m nebo tlakov\u00e9m nam\u00e1h\u00e1n\u00ed:<\/p>\n<p>E = \u03c3\/\u03b5<\/p>\n<p>Jednodu\u0161e \u0159e\u010deno, Young\u016fv modul ud\u00e1v\u00e1, jak velk\u00e1 s\u00edla je pot\u0159eba k prodlou\u017een\u00ed nebo stla\u010den\u00ed materi\u00e1lu o ur\u010ditou d\u00e9lku.  Vy\u0161\u0161\u00ed hodnota Youngova modulu znamen\u00e1 v\u011bt\u0161\u00ed tuhost materi\u00e1lu.  Jednotkou Youngova modulu je Pascal (Pa).<\/p>\n<p>Young\u016fv modul v anizotropn\u00edch piezokeradik\u00e1ch<\/p>\n<p>Piezokeradika jsou v\u0161ak obecn\u011b anizotropn\u00ed materi\u00e1ly, co\u017e znamen\u00e1, \u017ee jejich vlastnosti se li\u0161\u00ed v z\u00e1vislosti na sm\u011bru.  To je d\u00e1no jejich krystalovou strukturou a zp\u016fsobem, jak\u00fdm jsou vyrobeny.  V d\u016fsledku toho nelze Young\u016fv modul jednodu\u0161e definovat jedn\u00edm \u010d\u00edslem. M\u00edsto toho se pou\u017e\u00edv\u00e1 tenzor Youngova modulu, kter\u00fd je reprezentov\u00e1n matic\u00ed.  Tato matice obsahuje r\u016fzn\u00e9 hodnoty Youngova modulu pro r\u016fzn\u00e9 sm\u011bry.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Sm\u011br<\/th>\n<th>Young\u016fv modul (GPa)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Pod\u00e9ln\u00fd (po sm\u011bru polarizace)<\/td>\n<td>60-70<\/td>\n<\/tr>\n<tr>\n<td>P\u0159\u00ed\u010dn\u00fd (kolmo na sm\u011br polarizace)<\/td>\n<td>50-60<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em>Pozn\u00e1mka: Hodnoty v tabulce jsou pouze ilustrativn\u00ed a li\u0161\u00ed se v z\u00e1vislosti na konkr\u00e9tn\u00ed piezoelektrick\u00e9 keramice a v\u00fdrobn\u00edm procesu.<\/em><\/p>\n<p>Vliv piezoelektrick\u00e9ho efektu na m\u011b\u0159en\u00ed Youngova modulu<\/p>\n<p>M\u011b\u0159en\u00ed Youngova modulu u piezokeradik je komplikov\u00e1no piezoelektrick\u00fdm efektem.  Tento efekt spo\u010d\u00edv\u00e1 ve vzniku elektrick\u00e9ho n\u00e1boje p\u0159i mechanick\u00e9m nam\u00e1h\u00e1n\u00ed a naopak.  P\u0159i m\u011b\u0159en\u00ed je tedy nutn\u00e9 br\u00e1t v \u00favahu vliv elektrick\u00e9ho pole na mechanick\u00e9 vlastnosti a naopak.  M\u011b\u0159en\u00ed se obvykle prov\u00e1d\u00ed bu\u010f p\u0159i konstantn\u00edm elektrick\u00e9m poli (E-konstantn\u00ed) nebo p\u0159i konstantn\u00edm n\u00e1boji (D-konstantn\u00ed).  V\u00fdsledn\u00e9 hodnoty Youngova modulu se pak li\u0161\u00ed v z\u00e1vislosti na zvolen\u00fdch podm\u00ednk\u00e1ch m\u011b\u0159en\u00ed.<\/p>\n<p>Praktick\u00e9 metody m\u011b\u0159en\u00ed Youngova modulu<\/p>\n<p>Existuje n\u011bkolik metod pro m\u011b\u0159en\u00ed Youngova modulu piezokeradik.  Mezi nej\u010dast\u011bj\u0161\u00ed pat\u0159\u00ed dynamick\u00e9 metody zalo\u017een\u00e9 na m\u011b\u0159en\u00ed rezonan\u010dn\u00edch frekvenc\u00ed vzork\u016f a statick\u00e9 metody vyu\u017e\u00edvaj\u00edc\u00ed tenzometry. V\u00fdb\u011br metody z\u00e1vis\u00ed na po\u017eadovan\u00e9 p\u0159esnosti a dostupn\u00e9m vybaven\u00ed.  V n\u011bkter\u00fdch p\u0159\u00edpadech se k m\u011b\u0159en\u00ed pou\u017e\u00edvaj\u00ed i sofistikovan\u00e9 numerick\u00e9 simulace.<\/p>\n<p>Z\u00e1v\u011br<\/p>\n<p>Young\u016fv modul piezokeradik je kl\u00ed\u010dov\u00fdm parametrem pro pochopen\u00ed jejich mechanick\u00e9ho chov\u00e1n\u00ed.  Vzhledem k anizotropii a piezoelektrick\u00e9mu efektu v\u0161ak jeho definice a m\u011b\u0159en\u00ed vy\u017eaduj\u00ed sofistikovan\u011bj\u0161\u00ed p\u0159\u00edstup ne\u017e u izotropn\u00edch materi\u00e1l\u016f.  P\u0159esn\u00e9 ur\u010den\u00ed Youngova modulu z\u00e1vis\u00ed na sm\u011bru nam\u00e1h\u00e1n\u00ed a na elektrick\u00fdch podm\u00ednk\u00e1ch m\u011b\u0159en\u00ed.  Pou\u017eit\u00ed vhodn\u00fdch metod m\u011b\u0159en\u00ed a interpretace v\u00fdsledk\u016f je nezbytn\u00e9 pro optim\u00e1ln\u00ed n\u00e1vrh a aplikaci piezokeradikov\u00fdch sou\u010d\u00e1stek.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Piezokeradika jsou materi\u00e1ly, jejich\u017e mechanick\u00e9 vlastnosti jsou \u00fazce sv\u00e1z\u00e1ny s jejich elektrick\u00fdmi vlastnostmi. Jedn\u00edm z kl\u00ed\u010dov\u00fdch parametr\u016f popisuj\u00edc\u00edch jejich mechanick\u00e9 chov\u00e1n\u00ed je Young\u016fv modul, kter\u00fd charakterizuje tuhost materi\u00e1lu. Jeho p\u0159esn\u00e1 definice a m\u011b\u0159en\u00ed v kontextu piezokeradiky v\u0161ak vy\u017eaduje hlub\u0161\u00ed pochopen\u00ed jejich piezoelektrick\u00fdch vlastnost\u00ed. Definice Youngova modulu v izotropn\u00edm materi\u00e1lu V p\u0159\u00edpad\u011b izotropn\u00edho materi\u00e1lu, tj. materi\u00e1lu,<\/p>\n","protected":false},"author":1,"featured_media":4869,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-63561","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/63561","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/comments?post=63561"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/63561\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/4869"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=63561"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=63561"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=63561"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}