{"id":589,"date":"2026-02-26T05:44:05","date_gmt":"2026-02-26T05:44:05","guid":{"rendered":"https:\/\/www.teartester.com\/?post_type=method&p=589"},"modified":"2026-02-27T08:59:17","modified_gmt":"2026-02-27T08:59:17","slug":"tear-strength-test","status":"publish","type":"method","link":"https:\/\/www.teartester.com\/cs\/method\/tear-strength-test\/","title":{"rendered":"Zkou\u0161ka pevnosti v tahu"},"content":{"rendered":"

Z\u00e1sady zkou\u0161ek definovan\u00e9 v norm\u011b ASTM D624<\/h2>\n\n\n\n

ASTM D624<\/a> popisuje pevnost v tahu jako maxim\u00e1ln\u00ed s\u00edlu pot\u0159ebnou k protr\u017een\u00ed, iniciaci nebo \u0161\u00ed\u0159en\u00ed trhliny d\u011blenou tlou\u0161\u0165kou vzorku. P\u0159i zkou\u0161ce pevnosti v tahu zkou\u0161e\u010dka p\u016fsob\u00ed konstantn\u00ed rychlost\u00ed k\u0159\u00ed\u017eov\u00e9 hlavy, dokud se pry\u017eov\u00fd vzorek zcela neprotrhne.<\/p>\n\n\n\n

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\"Test<\/figure>\n<\/div>\n\n\n\n
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Zkou\u0161ka pevnosti v tahu pro pry\u017e a elastomery<\/h2>\n\n\n\n

A zkou\u0161ka odolnosti proti roztr\u017een\u00ed<\/strong> prov\u00e1d\u00ed \u0159\u00edzenou deformaci v tahu na p\u0159ipraven\u00e9m vzorku pomoc\u00ed tahov\u00e9ho zku\u0161ebn\u00edho stroje. Zkou\u0161ka pokra\u010duje, dokud nedojde k \u00fapln\u00e9mu p\u0159etr\u017een\u00ed. Proto\u017ee pry\u017e a elastomery vykazuj\u00ed slo\u017eit\u00e9 deforma\u010dn\u00ed chov\u00e1n\u00ed, klade norma ASTM D624 d\u016fraz na d\u016fslednou p\u0159\u00edpravu vzork\u016f, jejich vyrovn\u00e1n\u00ed a rychlost zkou\u0161ky, aby se zajistila opakovatelnost v\u00fdsledk\u016f.<\/p>\n\n\n\n

Je d\u016fle\u017eit\u00e9 si uv\u011bdomit, \u017ee pry\u017e a elastomery<\/strong> reaguj\u00ed na trh\u00e1n\u00ed r\u016fzn\u011b v z\u00e1vislosti na slo\u017een\u00ed, vytvrzen\u00ed, obsahu plniva a orientaci. Norma ASTM D624 proto definuje n\u011bkolik typ\u016f vzork\u016f, z nich\u017e ka\u017ed\u00fd je navr\u017een tak, aby reprezentoval jin\u00fd mechanismus trh\u00e1n\u00ed, nikoliv jednu univerz\u00e1ln\u00ed hodnotu.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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P\u0159\u00edprava vzorku a postup zkou\u0161ky<\/h2>\n\n\n\n

P\u0159esn\u00e9 testov\u00e1n\u00ed odolnosti proti roztr\u017een\u00ed za\u010d\u00edn\u00e1 pe\u010dlivou p\u0159\u00edpravou vzorku. Vzorky pry\u017ee mus\u00ed m\u00edt stejnou tlou\u0161\u0165ku, \u010dist\u00e9 hrany a p\u0159esnou geometrii. Jak\u00e1koli nepravidelnost m\u016f\u017ee v\u00fdrazn\u011b ovlivnit v\u00fdsledky zkou\u0161ky.<\/p>\n\n\n\n

Upevn\u011bte vzorek centr\u00e1ln\u011b do \u00fachyt\u016f tahov\u00e9ho zku\u0161ebn\u00edho stroje a zajist\u011bte jeho spr\u00e1vn\u00e9 vyrovn\u00e1n\u00ed, aby nedoch\u00e1zelo k p\u016fsoben\u00ed ohybov\u00fdch nebo torzn\u00edch sil. P\u016fsobte na vzorek tahovou z\u00e1t\u011b\u017e\u00ed p\u0159i stanoven\u00e9 konstantn\u00ed rychlosti, dokud nedojde k p\u0159etr\u017een\u00ed. Zaznamenejte k\u0159ivku s\u00edla-posunut\u00ed a ur\u010dete \u0161pi\u010dkov\u00e9 nebo pr\u016fm\u011brn\u00e9 s\u00edly podle zvolen\u00e9ho typu vzorku.<\/p>\n<\/div>\n\n\n\n

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\"Pr\u016fvodce<\/figure>\n<\/div>\n<\/div>\n\n\n\n

Pro\u010d je zkou\u0161ka pevnosti v tahu d\u016fle\u017eit\u00e1 v gum\u00e1rensk\u00fdch aplikac\u00edch?<\/h2>\n\n\n\n

V provozu pry\u017eov\u00e9 v\u00fdrobky z\u0159\u00eddka selh\u00e1vaj\u00ed pouze v d\u016fsledku rovnom\u011brn\u00e9ho rozta\u017een\u00ed. M\u00edsto toho porucha \u010dasto za\u010d\u00edn\u00e1 na ostr\u00fdch hran\u00e1ch, usazen\u00fdch \u010d\u00e1stic\u00edch nebo lokalizovan\u00fdch m\u00edstech nam\u00e1h\u00e1n\u00ed. Zkou\u0161ky pevnosti v tahu pom\u00e1haj\u00ed konstrukt\u00e9r\u016fm pochopit, jak rychle a snadno m\u016f\u017ee trhlina po sv\u00e9m vzniku nar\u016fst.<\/p>\n\n\n\n

Pro t\u00fdmy kontroly kvality je test pevnosti v tahu podporou pro porovn\u00e1v\u00e1n\u00ed materi\u00e1l\u016f, kontrolu proces\u016f a vstupn\u00ed kontrolu. Konstrukt\u00e9r\u016fm v\u00fdrobk\u016f poskytuje p\u0159ehled o vhodnosti materi\u00e1lu pro n\u00e1ro\u010dn\u00e9 aplikace, jako jsou dynamick\u00e1 t\u011bsn\u011bn\u00ed nebo prost\u0159ed\u00ed n\u00e1chyln\u00e1 k od\u011bru.<\/p>","protected":false},"featured_media":0,"parent":0,"template":"","meta":{"_acf_changed":true},"class_list":["post-589","method","type-method","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.teartester.com\/cs\/wp-json\/wp\/v2\/method\/589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.teartester.com\/cs\/wp-json\/wp\/v2\/method"}],"about":[{"href":"https:\/\/www.teartester.com\/cs\/wp-json\/wp\/v2\/types\/method"}],"wp:attachment":[{"href":"https:\/\/www.teartester.com\/cs\/wp-json\/wp\/v2\/media?parent=589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}