Ultrazvukov\u00e9 vlny, s frekvenc\u00ed nad 20 kHz, nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oborech, od medic\u00edny po pr\u016fmysl. Pochopen\u00ed toho, jak\u00e9 materi\u00e1ly tyto vlny blokuj\u00ed, je kl\u00ed\u010dov\u00e9 pro efektivn\u00ed design a aplikaci ultrazvukov\u00fdch syst\u00e9m\u016f. Neexistuje \u017e\u00e1dn\u00fd materi\u00e1l, kter\u00fd by ultrazvuk zcela absorboval, ale n\u011bkter\u00e9 materi\u00e1ly jsou mnohem efektivn\u011bj\u0161\u00ed v jeho tlumen\u00ed ne\u017e jin\u00e9.<\/p>\n
Hustota a akustick\u00e1 impedance<\/p>\n
Jedn\u00edm z nejd\u016fle\u017eit\u011bj\u0161\u00edch faktor\u016f ovliv\u0148uj\u00edc\u00edch pr\u016fnik ultrazvukov\u00fdch vln je hustota materi\u00e1lu a jeho akustick\u00e1 impedance. Akustick\u00e1 impedance je sou\u010din hustoty materi\u00e1lu a rychlosti zvuku v n\u011bm. \u010c\u00edm v\u011bt\u0161\u00ed je rozd\u00edl akustick\u00e9 impedance mezi dv\u011bma materi\u00e1ly (nap\u0159. mezi m\u00e9diem, ve kter\u00e9m se ultrazvuk \u0161\u00ed\u0159\u00ed, a materi\u00e1lem, kter\u00fd m\u00e1 blokovat), t\u00edm v\u011bt\u0161\u00ed je odraz ultrazvuku na rozhran\u00ed. Materi\u00e1ly s vysokou akustickou impedanc\u00ed, jako je ocel nebo olovo, odr\u00e1\u017e\u00ed zna\u010dnou \u010d\u00e1st ultrazvukov\u00e9 energie.<\/p>\n
Materi\u00e1l\nHustota (kg\/m\u00b3)\nRychlost zvuku (m\/s)\nAkustick\u00e1 impedance (MRayl)\n\nVzduch\n1.2\n343\n0.41\n\nVoda\n1000\n1480\n1.48\n\nOcel\n7850\n5960\n46.7\n\nOlovo\n11340\n1200\n13.6<\/code><\/pre>\nAbsorpce ultrazvuku<\/p>\n
Krom\u011b odrazu hraje d\u016fle\u017eitou roli i absorpce ultrazvukov\u00e9 energie v materi\u00e1lu. N\u011bkter\u00e9 materi\u00e1ly, nap\u0159\u00edklad m\u011bkk\u00e9 pry\u017ee nebo por\u00e9zn\u00ed materi\u00e1ly, absorbuj\u00ed ultrazvukov\u00e9 vlny efektivn\u011bji ne\u017e tvrd\u00e9 a hust\u00e9 materi\u00e1ly. Absorpce z\u00e1vis\u00ed na frekvenci ultrazvuku a na vlastnostech materi\u00e1lu, jako je jeho struktura a slo\u017een\u00ed. Por\u00e9zn\u00ed materi\u00e1ly s vysokou p\u00f3rovitost\u00ed sni\u017euj\u00ed intenzitu ultrazvuku d\u00edky t\u0159en\u00ed a rozptylu energie v p\u00f3rech.<\/p>\n
Tlumen\u00ed ultrazvuku v r\u016fzn\u00fdch materi\u00e1lech<\/p>\n
R\u016fzn\u00e9 materi\u00e1ly tlumen\u00ed ultrazvukov\u00fdch vln se li\u0161\u00ed. Nap\u0159\u00edklad, siln\u00e1 vrstva gumy m\u016f\u017ee efektivn\u011b utlumit ultrazvukov\u00e9 vlny s ni\u017e\u0161\u00ed frekvenc\u00ed. Naopak, tenk\u00e1 vrstva oceli m\u016f\u017ee odr\u00e1\u017eet zna\u010dnou \u010d\u00e1st energie, ale m\u00e9n\u011b ji absorbovat. V\u00fdb\u011br materi\u00e1lu pro blokov\u00e1n\u00ed ultrazvuku z\u00e1vis\u00ed na po\u017eadovan\u00e9 \u00farovni tlumen\u00ed a frekvenci ultrazvuku. V praxi se \u010dasto pou\u017e\u00edvaj\u00ed kombinace materi\u00e1l\u016f s r\u016fzn\u00fdmi vlastnostmi pro dosa\u017een\u00ed optim\u00e1ln\u00edho v\u00fdsledku.<\/p>\n
Aplikace blokov\u00e1n\u00ed ultrazvuku<\/p>\n
Blokov\u00e1n\u00ed ultrazvuku m\u00e1 \u0161irok\u00e9 uplatn\u011bn\u00ed v r\u016fzn\u00fdch oblastech. V medic\u00edn\u011b se pou\u017e\u00edvaj\u00ed materi\u00e1ly pro utlumen\u00ed ultrazvuku v ur\u010dit\u00fdch \u010d\u00e1stech t\u011bla, aby se zabr\u00e1nilo ne\u017e\u00e1douc\u00edmu \u0161\u00ed\u0159en\u00ed ultrazvukov\u00fdch vln. V pr\u016fmyslu se pou\u017e\u00edv\u00e1 pro ochranu citliv\u00fdch za\u0159\u00edzen\u00ed p\u0159ed ultrazvukov\u00fdm ru\u0161en\u00edm. V n\u011bkter\u00fdch aplikac\u00edch, jako je nap\u0159\u00edklad ultrazvukov\u00e9 \u010di\u0161t\u011bn\u00ed, je nutn\u00e9 naopak zajistit co nejlep\u0161\u00ed pr\u016fnik ultrazvuku do \u010di\u0161t\u011bn\u00e9ho materi\u00e1lu.<\/p>\n
Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee neexistuje jeden univerz\u00e1ln\u00ed materi\u00e1l pro blokov\u00e1n\u00ed ultrazvuku. V\u00fdb\u011br vhodn\u00e9ho materi\u00e1lu z\u00e1vis\u00ed na \u0159ad\u011b faktor\u016f, v\u010detn\u011b frekvence ultrazvuku, po\u017eadovan\u00e9 \u00farovn\u011b tlumen\u00ed a dal\u0161\u00edch specifick\u00fdch po\u017eadavk\u016f aplikace. Kombinace r\u016fzn\u00fdch materi\u00e1l\u016f s r\u016fzn\u00fdmi vlastnostmi je \u010dasto nejefektivn\u011bj\u0161\u00ed strategi\u00ed pro dosa\u017een\u00ed po\u017eadovan\u00e9ho v\u00fdsledku.<\/p>\n","protected":false},"excerpt":{"rendered":"
Ultrazvukov\u00e9 vlny, s frekvenc\u00ed nad 20 kHz, nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oborech, od medic\u00edny po pr\u016fmysl. Pochopen\u00ed toho, jak\u00e9 materi\u00e1ly tyto vlny blokuj\u00ed, je kl\u00ed\u010dov\u00e9 pro efektivn\u00ed design a aplikaci ultrazvukov\u00fdch syst\u00e9m\u016f. Neexistuje \u017e\u00e1dn\u00fd materi\u00e1l, kter\u00fd by ultrazvuk zcela absorboval, ale n\u011bkter\u00e9 materi\u00e1ly jsou mnohem efektivn\u011bj\u0161\u00ed v jeho tlumen\u00ed ne\u017e jin\u00e9. Hustota a akustick\u00e1<\/p>\n","protected":false},"author":1,"featured_media":26471,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-57386","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\/57386","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=57386"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/57386\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/26471"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=57386"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=57386"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=57386"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}