{"id":974,"date":"2025-12-12T00:18:40","date_gmt":"2025-12-12T00:18:40","guid":{"rendered":"https:\/\/www.materialstests.com\/?p=974"},"modified":"2025-12-12T00:19:01","modified_gmt":"2025-12-12T00:19:01","slug":"tension-and-compression-testing","status":"publish","type":"post","link":"https:\/\/www.materialstests.com\/sk\/resources\/tension-and-compression-testing.html","title":{"rendered":"Testovanie \u0165ahom a tlakom"},"content":{"rendered":"<h3 class=\"wp-block-heading\">\u00davod<\/h3>\n\n\n\n<p>V stroj\u00e1rstve s\u00fa materi\u00e1ly vystaven\u00e9 r\u00f4znym typom za\u0165a\u017eenia. Za\u0165a\u017eenia, ktor\u00fdm m\u00f4\u017eu by\u0165 materi\u00e1ly vystaven\u00e9, mo\u017eno vymenova\u0165 ako \u0165ahov\u00e9, tlakov\u00e9, ohybov\u00e9, strihov\u00e9 alebo kr\u00fatiace. Z\u00e1rove\u0148 sa tieto za\u0165a\u017eenia m\u00f4\u017eu l\u00ed\u0161i\u0165 staticky alebo dynamicky. Materi\u00e1l m\u00f4\u017ee musie\u0165 odol\u00e1va\u0165 jedn\u00e9mu alebo viacer\u00fdm z t\u00fdchto za\u0165a\u017een\u00ed s\u00fa\u010dasne. V takom pr\u00edpade je potrebn\u00e9 vedie\u0165, ktor\u00fd materi\u00e1l sa m\u00e1 za ak\u00fdch podmienok pou\u017ei\u0165. Na zoskupenie materi\u00e1lov sa pomocou sk\u00fa\u0161ok sleduj\u00fa ich reakcie pri ur\u010dit\u00fdch za\u0165a\u017eeniach, a t\u00fdm sa zis\u0165uj\u00fa mechanick\u00e9 vlastnosti materi\u00e1lov.<\/p>\n\n\n\n<p>Sk\u00fa\u0161ky na z\u00edskanie elastick\u00fdch vlastnost\u00ed m\u00f4\u017eeme rozdeli\u0165 na statick\u00e9 a dynamick\u00e9. Aby bola sk\u00fa\u0161ka statick\u00e1, mus\u00ed sila p\u00f4sobi\u0165 s maxim\u00e1lnou frekvenciou 1 Hz, kon\u0161tantne a len jedenkr\u00e1t. V tomto pr\u00edpade je nap\u00e4tie kon\u0161tantn\u00e9 a pomer pred\u013a\u017eenia je pri statickej sk\u00fa\u0161ke men\u0161\u00ed ako 0,25. Pri t\u00fdchto typoch za\u0165a\u017eenia sa pou\u017e\u00edvaj\u00fa dynamick\u00e9 sk\u00fa\u0161ky, preto\u017ee statick\u00e9 sk\u00fa\u0161ky nem\u00f4\u017eu vytvori\u0165 vhodn\u00fd model pre n\u00e1hle sa meniace za\u0165a\u017eenie. Pri dynamick\u00fdch sk\u00fa\u0161kach je za\u0165a\u017eenie premenliv\u00e9 a na vzorku p\u00f4sob\u00ed s\u00ednusov\u00e1 deform\u00e1cia. Tieto sk\u00fa\u0161ky sa m\u00f4\u017eu vykon\u00e1va\u0165 aj pri vysok\u00fdch alebo n\u00edzkych teplot\u00e1ch. V\u00fdsledkom dynamick\u00fdch sk\u00fa\u0161ok s\u00fa inform\u00e1cie o tvrdosti a tlmen\u00ed. \u00danavov\u00e9 sk\u00fa\u0161ky m\u00f4\u017eeme sk\u00fama\u0165 ako pododvetvie dynamick\u00fdch sk\u00fa\u0161ok. Za\u0165a\u017eenie sa aplikuje cyklicky. Tieto sk\u00fa\u0161ky sa vykon\u00e1vaj\u00fa s cyklami \u0165ah - \u0165ah, tlak - stla\u010denie alebo tlak - sp\u00e4tn\u00fd \u0165ah. V\u00fdsledkom \u00fanavovej sk\u00fa\u0161ky je ur\u010denie \u017eivotnosti materi\u00e1lov. \u00danavovou sk\u00fa\u0161kou sa ur\u010duje aj \u00fanavov\u00e1 pevnos\u0165 a odolnos\u0165 proti praskaniu.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img fetchpriority=\"high\" decoding=\"async\" width=\"800\" height=\"800\" src=\"https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing.jpg\" alt=\"Testovanie \u0165ahom a tlakom\" class=\"wp-image-977\" srcset=\"https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing.jpg 800w, https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing-300x300.jpg 300w, https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing-150x150.jpg 150w, https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing-768x768.jpg 768w, https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing-600x600.jpg 600w, https:\/\/www.materialstests.com\/wp-content\/uploads\/2025\/12\/Tension-and-Compression-Testing-100x100.jpg 100w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">&nbsp;<\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">Sk\u00fa\u0161ka \u0165ahom<\/h3>\n\n\n\n<p>Sk\u00fa\u0161ka \u0165ahom je jednou z najbe\u017enej\u0161\u00edch sk\u00fa\u0161ok v stroj\u00e1rstve na ur\u010denie pevnostn\u00fdch vlastnost\u00ed materi\u00e1lov. Vykon\u00e1va sa na ur\u010denie mechanick\u00fdch vlastnost\u00ed izotropn\u00fdch materi\u00e1lov. T\u00e1to sk\u00fa\u0161ka je v podstate zalo\u017een\u00e1 na p\u00f4soben\u00ed \u0165ahovej sily na vzorku z proti\u013eahl\u00fdch str\u00e1n v rovnakom smere a na sledovan\u00ed nap\u00e4tia na materi\u00e1li a\u017e do poru\u0161enia materi\u00e1lu. V\u00fdsledkom \u0165ahovej sk\u00fa\u0161ky je medza klzu, maxim\u00e1lna medza pevnosti v \u0165ahu, \u0165a\u017enos\u0165, Youngov modul, modul pru\u017enosti v \u0161myku a Poissonov pomer materi\u00e1lu.<\/p>\n\n\n\n<p>Krivky nap\u00e4tia a deform\u00e1cie<\/p>\n\n\n\n<p>Krivky nap\u00e4tia a deform\u00e1cie<\/p>\n\n\n\n<p>Nomin\u00e1lne \u0165ahov\u00e9 nap\u00e4tie p\u00f4sobiace na materi\u00e1l po\u010das sk\u00fa\u0161ky je nasledovn\u00e9:<\/p>\n\n\n\n<p>Kde F je \u0165ahov\u00e1 sila a A_0 je plocha prierezu v \u0165ahu. A deform\u00e1cia je definovan\u00e1 ako;<\/p>\n\n\n\n<p>Kde L_0 je po\u010diato\u010dn\u00e1 d\u013a\u017eka vzorky a \u0394_L je pred\u013a\u017eenie materi\u00e1lu po sk\u00fa\u0161ke.<\/p>\n\n\n\n<p>Pomocou hodn\u00f4t z\u00edskan\u00fdch zo sk\u00fa\u0161ky sa z\u00edska krivka nap\u00e4tia a deform\u00e1cie. T\u00e1to krivka odha\u013euje bod poru\u0161enia materi\u00e1lu, medzu klzu, maxim\u00e1lnu pevnos\u0165 v \u0165ahu a stav krehkosti a \u0165a\u017enosti. \u010eal\u0161ou v\u00fdhodou je, \u017ee poskytuje inform\u00e1cie bez oh\u013eadu na rozmery materi\u00e1lu.<\/p>\n\n\n\n<p>Uveden\u00fd diagram zn\u00e1zor\u0148uje krivku nap\u00e4tia a deform\u00e1cie krehk\u00e9ho materi\u00e1lu.<\/p>\n\n\n\n<p>Pre v\u00e4\u010d\u0161inu kriviek je po\u010diato\u010dn\u00e1 \u010das\u0165 line\u00e1rna. Hodnota medze klzu sa z\u00edska na krivke, ke\u010f sa krivka rovnobe\u017en\u00e1 so sklonom krivky vedie z bodu, kde je pred\u013a\u017eenie v krivke nap\u00e4tie-deform\u00e1cia 0,2%. Pomocou medze klzu m\u00f4\u017eeme ur\u010di\u0165 maxim\u00e1lne nap\u00e4tie, ktor\u00e9 materi\u00e1l znesie bez trval\u00e9ho po\u0161kodenia. A\u017e do tohto bodu je predmet v pru\u017enej oblasti. Potom sa materi\u00e1l dost\u00e1va do plastickej oblasti, kde sily na\u0148 p\u00f4sobiace sp\u00f4sobuj\u00fa trval\u00e9 po\u0161kodenie.<\/p>\n\n\n\n<p>V\u00fdnosov\u00e9 nap\u00e4tie<\/p>\n\n\n\n<p>Sklon pomyselnej priamky, ktor\u00fa sme narysovali na zistenie medze klzu, n\u00e1m ud\u00e1va Youngov modul, ktor\u00fd je d\u00f4le\u017eitou vlastnos\u0165ou materi\u00e1lu. Youngov modul sa z\u00edska takto:<\/p>\n\n\n\n<p>Nasleduj\u00faca rovnica predstavuje Poissonov pomer, ktor\u00fd je z\u00e1pornou hodnotou pomeru vodorovn\u00e9ho posunu k zvisl\u00e9mu posunu:<\/p>\n\n\n\n<p>Test<\/p>\n\n\n\n<p>V\u00e4\u010d\u0161ina prierezov vzoriek pou\u017eit\u00fdch pri sk\u00fa\u0161ke \u0165ahom je zn\u00e1zornen\u00e1 na obr\u00e1zku. Vzorky m\u00f4\u017eu by\u0165 vytvoren\u00e9 ako plech alebo valec.<\/p>\n\n\n\n<p>V z\u00e1vislosti od r\u00f4znych materi\u00e1lov a \u00farovn\u00ed citlivosti merania sa m\u00f4\u017eu pou\u017ei\u0165 r\u00f4zne typy up\u00ednania. Ka\u017ed\u00fd sp\u00f4sob viazania m\u00e1 svoje vlastn\u00e9 v\u00fdhody a nev\u00fdhody.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Test kompresie<\/h3>\n\n\n\n<p>Sk\u00fa\u0161ka stla\u010den\u00edm ukazuje, ako sa materi\u00e1ly spr\u00e1vaj\u00fa pri stla\u010den\u00ed alebo rozdrven\u00ed. Sk\u00fa\u0161ka zvy\u010dajne trv\u00e1 dovtedy, k\u00fdm sa l\u00e1tka nerozlo\u017e\u00ed alebo k\u00fdm sa nedosiahne vopred stanoven\u00e1 hranica. Vypo\u010d\u00edta sa tak za\u0165a\u017eenie, ktor\u00e9 materi\u00e1l vydr\u017e\u00ed pred roztrhnut\u00edm, a rozsah jeho degrad\u00e1cie do tohto bodu. Na testovanie sa materi\u00e1l \u010dasto zahrieva alebo ochladzuje a p\u00f4sob\u00ed na\u0148 tlakov\u00e1 sila v mnoh\u00fdch smeroch. Sk\u00fa\u0161ky sa v\u0161ak m\u00f4\u017eu vykon\u00e1va\u0165 pri r\u00f4znych nastaveniach.<\/p>\n\n\n\n<p>Materi\u00e1ly s vysokou pevnos\u0165ou v \u0165ahu maj\u00fa spravidla n\u00edzku pevnos\u0165 v tlaku. Z tohto d\u00f4vodu sa tieto materi\u00e1ly sk\u00famaj\u00fa sk\u00fa\u0161kou v tlaku. Materi\u00e1ly, na ktor\u00fdch sa vykon\u00e1va najviac sk\u00fa\u0161ok v tlaku, s\u00fa vo v\u0161eobecnosti krehk\u00e9 materi\u00e1ly, napr\u00edklad kompozitn\u00e9 materi\u00e1ly, bet\u00f3n, drevo, kov a tehlov\u00e9 materi\u00e1ly; polym\u00e9ry, plasty a peny.<\/p>\n\n\n\n<p>V\u00fdsledkom tlakovej sk\u00fa\u0161ky je krivka sily a deform\u00e1cie. Sila sa potom prepo\u010d\u00edta na nap\u00e4tie a vytvor\u00ed sa krivka nap\u00e4tie-deform\u00e1cia. T\u00e1to krivka je ve\u013emi podobn\u00e1 krivke nap\u00e4tie-deform\u00e1cia pri sk\u00fa\u0161ke \u0165ahom. Len osi s\u00fa v smere, ktor\u00fd zn\u00e1zor\u0148uje skr\u00e1tenie.<\/p>\n\n\n\n<p>Nap\u00e4tie v tlaku - % Deform\u00e1cia v tlaku<\/p>\n\n\n\n<p>V\u00fdpo\u010dty pri sk\u00fa\u0161ke \u0165ahom platia aj pre sk\u00fa\u0161ku tlakom. tlakov\u00e1 sila sa vyjadruje ako;<\/p>\n\n\n\n<p>Drvenie<\/p>\n\n\n\n<p>Drvenie sa pou\u017e\u00edva na vyjadrenie toho, o ko\u013eko sa materi\u00e1l po\u010das testu skr\u00e1til.<\/p>\n\n\n\n<p>Vyjadrite zdrvenie.<\/p>\n\n\n\n<p>Opuchy<\/p>\n\n\n\n<p>Napu\u010diavanie je rast prierezu testovan\u00e9ho materi\u00e1lu. \u0164ahav\u00e9 materi\u00e1ly s\u00fa n\u00e1chylnej\u0161ie na napu\u010diavanie. Formalizuje sa pod\u013ea:<\/p>\n\n\n\n<p>Test<\/p>\n\n\n\n<p>Krehk\u00e9 materi\u00e1ly s\u00fa zvy\u010dajne predmetom sk\u00fa\u0161ok v tlaku. Tlakov\u00e9 charakteristiky tuh\u00fdch pien uv\u00e1dza norma ISO 844 ako pr\u00edklad z noriem. V tejto norme s\u00fa uveden\u00e9 hodnoty prierezu a formy, hodnoty teploty a vlhkosti a predpokladan\u00e9 v\u00fdsledky vzoriek. V kPa sa uv\u00e1dzaj\u00fa nap\u00e4tia.<\/p>\n\n\n\n<p>Hodnota pru\u017enosti pri stla\u010den\u00ed v norme je tak\u00e1to:<\/p>\n\n\n\n<p>Tu \u03c3_e je sila na konci konven\u010dnej pru\u017enej oblasti, h_0 je po\u010diato\u010dn\u00e1 hr\u00fabka materi\u00e1lu a x_e je dr\u00e1ha, ktor\u00fa prekon\u00e1va sila generuj\u00faca nap\u00e4tie.<\/p>\n\n\n\n<p>Nasleduje nieko\u013eko noriem vyvinut\u00fdch pre tlakov\u00e9 sk\u00fa\u0161ky:<\/p>\n\n\n\n<p>ASTM D575-91 - \u0160tandardn\u00e9 sk\u00fa\u0161obn\u00e9 met\u00f3dy pre vlastnosti gumy v tlaku<\/p>\n\n\n\n<p>ASTM E9-19 - \u0160tandardn\u00e9 sk\u00fa\u0161obn\u00e9 met\u00f3dy sk\u00fa\u0161ania kovov\u00fdch materi\u00e1lov v tlaku pri izbovej teplote<\/p>\n\n\n\n<p>TS EN ISO 14126 - Plastov\u00e9 kompozity vystu\u017een\u00e9 vl\u00e1knami - Stanovenie tlakov\u00fdch vlastnost\u00ed v rovinnom smere<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">&nbsp;<\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">Opis techniky<\/h3>\n\n\n\n<p>Vyhodnotenie mechanick\u00e9ho spr\u00e1vania sa vzorky v podmienkach \u0165ahu a tlaku m\u00f4\u017ee by\u0165 vykonan\u00e9 s cie\u013eom poskytn\u00fa\u0165 z\u00e1kladn\u00e9 \u00fadaje o vlastnostiach materi\u00e1lu, ktor\u00e9 s\u00fa rozhoduj\u00face pre n\u00e1vrh s\u00fa\u010diastky a pos\u00fadenie prev\u00e1dzkov\u00fdch vlastnost\u00ed. Po\u017eiadavky na hodnoty pevnosti v \u0165ahu a tlaku a met\u00f3dy sk\u00fa\u0161ania t\u00fdchto vlastnost\u00ed s\u00fa \u0161pecifikovan\u00e9 v r\u00f4znych norm\u00e1ch pre \u0161irok\u00fa \u0161k\u00e1lu materi\u00e1lov. Testovanie sa m\u00f4\u017ee vykon\u00e1va\u0165 na strojovo opracovan\u00fdch vzork\u00e1ch materi\u00e1lu alebo na plnorozmern\u00fdch alebo zmen\u0161en\u00fdch modeloch skuto\u010dn\u00fdch komponentov. Tieto sk\u00fa\u0161ky sa zvy\u010dajne vykon\u00e1vaj\u00fa pomocou univerz\u00e1lneho mechanick\u00e9ho sk\u00fa\u0161obn\u00e9ho pr\u00edstroja.<\/p>\n\n\n\n<p>\u0164ahov\u00e1 sk\u00fa\u0161ka je met\u00f3da na ur\u010denie spr\u00e1vania sa materi\u00e1lov pri axi\u00e1lnom za\u0165a\u017een\u00ed \u0165ahom. Sk\u00fa\u0161ky sa vykon\u00e1vaj\u00fa upevnen\u00edm vzorky do sk\u00fa\u0161obn\u00e9ho zariadenia a n\u00e1sledn\u00fdm p\u00f4soben\u00edm sily na vzorku oddelen\u00edm prie\u010dnych hlav\u00edc sk\u00fa\u0161obn\u00e9ho stroja. R\u00fdchlos\u0165 kr\u00ed\u017eovej hlavy sa m\u00f4\u017ee meni\u0165, aby sa kontrolovala r\u00fdchlos\u0165 deform\u00e1cie sk\u00fa\u0161obnej vzorky. \u00dadaje zo sk\u00fa\u0161ky sa pou\u017e\u00edvaj\u00fa na ur\u010denie pevnosti v \u0165ahu, medze klzu a modulu pru\u017enosti. Meranie rozmerov vzorky po sk\u00fa\u0161ke poskytuje aj hodnoty redukcie plochy a pred\u013a\u017eenia na charakterizovanie \u0165a\u017enosti materi\u00e1lu. \u0164ahov\u00e9 sk\u00fa\u0161ky sa m\u00f4\u017eu vykon\u00e1va\u0165 na mnoh\u00fdch materi\u00e1loch vr\u00e1tane kovov, plastov, vl\u00e1kien, lepidiel a gumy. Sk\u00fa\u0161ky sa m\u00f4\u017eu vykon\u00e1va\u0165 pri teplot\u00e1ch pod teplotou a pri zv\u00fd\u0161en\u00fdch teplot\u00e1ch.<br><br>Sk\u00fa\u0161ka v tlaku je met\u00f3da na ur\u010denie spr\u00e1vania sa materi\u00e1lov pri za\u0165a\u017een\u00ed v tlaku. Sk\u00fa\u0161ky tlakom sa vykon\u00e1vaj\u00fa tak, \u017ee sa sk\u00fa\u0161obn\u00e1 vzorka za\u0165a\u017e\u00ed medzi dvoma doskami a potom sa na vzorku p\u00f4sob\u00ed silou pohybom prie\u010dnych hr\u00e1n. Po\u010das sk\u00fa\u0161ky sa vzorka stl\u00e1\u010da a zaznamen\u00e1va sa deform\u00e1cia v z\u00e1vislosti od p\u00f4sobiaceho za\u0165a\u017eenia. Sk\u00fa\u0161ka stla\u010den\u00edm sa pou\u017e\u00edva na ur\u010denie medze pru\u017enosti, medze \u00famernosti, medze klzu, medze klzu a (v pr\u00edpade niektor\u00fdch materi\u00e1lov) pevnosti v tlaku.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">&nbsp;<\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">Analytick\u00e9 inform\u00e1cie<\/h3>\n\n\n\n<p><strong>Pevnos\u0165 v tlaku<\/strong>&nbsp;- Pevnos\u0165 v tlaku je maxim\u00e1lne tlakov\u00e9 nap\u00e4tie, ktor\u00e9 je materi\u00e1l schopn\u00fd vydr\u017ea\u0165 bez poru\u0161enia. Krehk\u00e9 materi\u00e1ly sa po\u010das sk\u00fa\u0161ky l\u00e1mu a maj\u00fa ur\u010dit\u00fa hodnotu pevnosti v tlaku. Pevnos\u0165 v tlaku tv\u00e1rnych materi\u00e1lov sa ur\u010duje pod\u013ea stup\u0148a ich deform\u00e1cie po\u010das sk\u00fa\u0161ky.<\/p>\n\n\n\n<p><strong>Limit pru\u017enosti<\/strong>&nbsp;- Medza pru\u017enosti je maxim\u00e1lne nap\u00e4tie, ktor\u00e9 m\u00f4\u017ee materi\u00e1l vydr\u017ea\u0165 bez trvalej deform\u00e1cie po odstr\u00e1nen\u00ed nap\u00e4tia.<\/p>\n\n\n\n<p><strong>Pred\u013a\u017eenie<\/strong>&nbsp;- Pred\u013a\u017eenie je ve\u013ekos\u0165 trval\u00e9ho pred\u013a\u017eenia vzorky, ktor\u00e1 bola poru\u0161en\u00e1 pri sk\u00fa\u0161ke \u0165ahom.<\/p>\n\n\n\n<p><strong>Moduly pru\u017enosti<\/strong>&nbsp;- Modul pru\u017enosti je pomer nap\u00e4tia (pod hranicou \u00famernosti) k deform\u00e1cii, t. j. sklon krivky nap\u00e4tie-deform\u00e1cia. Pova\u017euje sa za mieru tuhosti alebo pevnosti kovu.<\/p>\n\n\n\n<p><strong>Proporcion\u00e1lny limit<\/strong>&nbsp;- Medza \u00famernosti je najv\u00e4\u010d\u0161ia ve\u013ekos\u0165 nap\u00e4tia, ktor\u00fa je materi\u00e1l schopn\u00fd dosiahnu\u0165 bez toho, aby sa odch\u00fdlil od line\u00e1rnej z\u00e1vislosti krivky nap\u00e4tia a deform\u00e1cie, t. j. bez vzniku plastickej deform\u00e1cie.<\/p>\n\n\n\n<p><strong>Zn\u00ed\u017eenie plochy<\/strong>&nbsp;- Zmen\u0161enie plochy je rozdiel medzi p\u00f4vodnou plochou prierezu vzorky v \u0165ahu a najmen\u0161ou plochou po zlome po sk\u00fa\u0161ke.<\/p>\n\n\n\n<p><strong>Kme\u0148<\/strong>&nbsp;- Deform\u00e1cia je zmena ve\u013ekosti alebo tvaru materi\u00e1lu vplyvom sily.<\/p>\n\n\n\n<p><strong>V\u00fdnosov\u00fd bod<\/strong>&nbsp;- Bod klzu je nap\u00e4tie v materi\u00e1li (zvy\u010dajne men\u0161ie ako maxim\u00e1lne dosiahnute\u013en\u00e9 nap\u00e4tie), pri ktorom doch\u00e1dza k n\u00e1rastu deform\u00e1cie bez zv\u00fd\u0161enia nap\u00e4tia. Bod klzu maj\u00fa len niektor\u00e9 kovy.<\/p>\n\n\n\n<p><strong>V\u00fd\u0165a\u017enos\u0165<\/strong>&nbsp;- Medza klzu je nap\u00e4tie, pri ktorom materi\u00e1l vykazuje ur\u010dit\u00fa odch\u00fdlku od line\u00e1rneho vz\u0165ahu medzi nap\u00e4t\u00edm a deform\u00e1ciou. Pre kovy sa \u010dasto pou\u017e\u00edva odch\u00fdlka 0,2%.<\/p>\n\n\n\n<p><strong>Pevnos\u0165 v \u0165ahu<\/strong>&nbsp;- Pevnos\u0165 v \u0165ahu alebo UTS je maxim\u00e1lne \u0165ahov\u00e9 nap\u00e4tie, ktor\u00e9 m\u00f4\u017ee materi\u00e1l vydr\u017ea\u0165 bez poru\u0161enia. Vypo\u010d\u00edta sa vydelen\u00edm maxim\u00e1lneho za\u0165a\u017eenia p\u00f4sobiaceho po\u010das \u0165ahovej sk\u00fa\u0161ky p\u00f4vodnou plochou prierezu vzorky.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">&nbsp;<\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">Typick\u00e9 aplik\u00e1cie<\/h3>\n\n\n\n<p><a href=\"https:\/\/www.materialstests.com\/sk\/products\/tensile-and-compression-tester.html\/\"><strong>\u0164ah a kompresia<\/strong><\/a>&nbsp;vlastnosti surov\u00edn na porovnanie so \u0161pecifik\u00e1ciami v\u00fdrobku<\/p>\n\n\n\n<p>Z\u00edskanie \u00fadajov o vlastnostiach materi\u00e1lu pre modelovanie met\u00f3dou kone\u010dn\u00fdch prvkov alebo in\u00fd n\u00e1vrh v\u00fdrobku pre po\u017eadovan\u00e9 mechanick\u00e9 spr\u00e1vanie a prev\u00e1dzkov\u00e9 vlastnosti.<\/p>\n\n\n\n<p>Simul\u00e1cia mechanick\u00fdch vlastnost\u00ed komponentov v prev\u00e1dzke<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">&nbsp;<\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">Vzorov\u00e9 po\u017eiadavky<\/h3>\n\n\n\n<p>\u0160tandardn\u00e9 \u0165ahov\u00e9 sk\u00fa\u0161ky kovov a plastov sa vykon\u00e1vaj\u00fa na \u0161peci\u00e1lne pripraven\u00fdch sk\u00fa\u0161obn\u00fdch vzork\u00e1ch. Tieto vzorky m\u00f4\u017eu by\u0165 opracovan\u00e9 valcov\u00e9 vzorky alebo vzorky z ploch\u00fdch dosiek (psie kosti). Sk\u00fa\u0161obn\u00e9 vzorky musia ma\u0165 \u0161pecifick\u00fd pomer d\u013a\u017eky k \u0161\u00edrke alebo priemeru v sk\u00fa\u0161obnej oblasti (meradle), aby sa dosiahli opakovate\u013en\u00e9 v\u00fdsledky a aby boli v s\u00falade so \u0161tandardom&nbsp;<a href=\"https:\/\/www.materialstests.com\/sk\/products\/tensile-and-compression-tester.html\/\">sk\u00fa\u0161obn\u00e1 met\u00f3da<\/a>&nbsp;po\u017eiadavky. R\u00farkov\u00e9 v\u00fdrobky, vl\u00e1kna a dr\u00f4ty mo\u017eno testova\u0165 v \u0165ahu v plnej ve\u013ekosti pomocou \u0161peci\u00e1lnych pr\u00edpravkov, ktor\u00e9 podporuj\u00fa optim\u00e1lne uchopenie a lokaliz\u00e1ciu poruchy.<\/p>\n\n\n\n<p>Najbe\u017enej\u0161ou vzorkou pou\u017e\u00edvanou na sk\u00fa\u0161ku tlakom je prav\u00fd kruhov\u00fd valec s ploch\u00fdmi koncami. M\u00f4\u017eu sa pou\u017ei\u0165 aj in\u00e9 tvary, ktor\u00e9 si v\u0161ak vy\u017eaduj\u00fa \u0161peci\u00e1lne pr\u00edpravky, aby sa zabr\u00e1nilo ich vybo\u010deniu. \u0160peci\u00e1lne konfigur\u00e1cie na sk\u00fa\u0161anie komponentov alebo simul\u00e1ciu prev\u00e1dzky z\u00e1visia od konkr\u00e9tneho sk\u00fa\u0161obn\u00e9ho stroja, ktor\u00fd sa m\u00e1 pou\u017ei\u0165.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Rozdiel medzi zariaden\u00edm na sk\u00fa\u0161ku \u0165ahom a tlakom<\/h2>\n\n\n\n<p>V pr\u00edpade \u0165ahov\u00fdch sk\u00fa\u0161ok sk\u00fa\u0161obn\u00fd stroj p\u00f4sob\u00ed \u0165ahov\u00fdm za\u0165a\u017een\u00edm alebo silou, ktor\u00e1 \u0165ah\u00e1 sk\u00fa\u0161obn\u00e9 vzorky od seba. V pr\u00edpade \u0165ahov\u00fdch sk\u00fa\u0161ok plastov sa sk\u00fa\u0161obn\u00e1 vzorka roz\u0165ahuje, aby sa zmerala pevnos\u0165 v \u0165ahu a \u010fal\u0161ie vlastnosti vr\u00e1tane tuhosti a medze klzu. Existuje nieko\u013eko spolo\u010dn\u00fdch priemyseln\u00fdch noriem, ktor\u00e9 poskytuj\u00fa dohodnut\u00e9 met\u00f3dy sk\u00fa\u0161ok plastov v \u0165ahu. Normy ASTM D638 a ISO 527-2 obsahuj\u00fa podobn\u00e9, ale odli\u0161n\u00e9 \u0161tandardizovan\u00e9 geometrie a rozmery sk\u00fa\u0161obn\u00fdch vzoriek. Tieto sk\u00fa\u0161ky si vy\u017eaduj\u00fa \u0165ahov\u00e9 \u00fachyty, od ktor\u00fdch sa o\u010dak\u00e1va, \u017ee uchopia vzorku a prisp\u00f4sobia sa jej sten\u010dovaniu po\u010das sk\u00fa\u0161obn\u00e9ho procesu. Toto pr\u00edslu\u0161enstvo sa l\u00ed\u0161i od lisovac\u00edch pr\u00edpravkov.&nbsp;<br><br>Pri tlakov\u00fdch sk\u00fa\u0161kach vyv\u00edja sk\u00fa\u0161obn\u00fd stroj tla\u010dn\u00e9 alebo tla\u010dn\u00e9 za\u0165a\u017eenie alebo silu, aby sa sk\u00fa\u0161obn\u00e1 vzorka zm\u00e1\u010dkla, a\u017e k\u00fdm sa neroztrhne alebo nezm\u00e1\u010dkne. Sk\u00fa\u0161ky stla\u010denia polym\u00e9rneho kon\u0161truk\u010dn\u00e9ho penov\u00e9ho materi\u00e1lu s\u00fa pokryt\u00e9&nbsp;<strong>ASTM D1621<\/strong>&nbsp;v ktorom sa uv\u00e1dza typ pou\u017eit\u00fdch kompresn\u00fdch dosiek a deflektometra. Sk\u00fa\u0161obn\u00e1 vzorka sa umiestni medzi sk\u00fa\u0161obn\u00e9 dosky na stla\u010denie, k\u00fdm ned\u00f4jde k poru\u0161eniu alebo prasknutiu bunkovej \u0161trukt\u00fary.<br><br>Univerz\u00e1lny sk\u00fa\u0161obn\u00fd stroj m\u00f4\u017ee vykon\u00e1va\u0165 sk\u00fa\u0161ky \u0165ahom aj tlakom. Kr\u00ed\u017eov\u00e1 hlava sa m\u00f4\u017ee pou\u017ei\u0165 na \u0165ahanie alebo stl\u00e1\u010danie sk\u00fa\u0161obnej vzorky, ktor\u00e1 je umiestnen\u00e1 medzi z\u00e1kladnou doskou a pohyblivou hlavou.<br><br>Pr\u00edpravky na \u0165ahov\u00e9 sk\u00fa\u0161ky alebo \u00fachytky a sn\u00edma\u010de \u0165ahu (zn\u00e1me ako extenzometer) nem\u00f4\u017eu vykon\u00e1va\u0165 tlakov\u00e9 sk\u00fa\u0161ky. Aj \u0165ahov\u00e9 \u00fachyty s\u00fa \u0161peci\u00e1lne prisp\u00f4soben\u00e9 tak, aby pokr\u00fdvali presn\u00fa geometriu a rozmery sk\u00fa\u0161obnej vzorky. Tlakov\u00e9 sk\u00fa\u0161obn\u00e9 klie\u0161te a defektometer s\u00fa tie\u017e schopn\u00e9 vykon\u00e1va\u0165 len tlakov\u00fa sk\u00fa\u0161ku, a preto s\u00fa v tomto pr\u00edpade potrebn\u00e9 obe sady pr\u00edslu\u0161enstva.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">&nbsp;<\/h2>\n\n\n\n<p>Ak chcete z\u00edska\u0165 viac inform\u00e1ci\u00ed o tomto v\u00fdrobku,&nbsp;<a href=\"https:\/\/www.materialstests.com\/sk\/contact-us.html\/\"><strong>nev\u00e1hajte n\u00e1s kontaktova\u0165.&nbsp;<\/strong><\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Introduction In engineering, materials are exposed to different types of loads. The loads that materials can be subjected to can be listed as tensile, compression, bending, shearing, or twisting. At the same time, these loads can differ statically or dynamically. The material may have to resist one or more of these loads at the same [&hellip;]<\/p>","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-974","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/posts\/974","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/comments?post=974"}],"version-history":[{"count":0,"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/posts\/974\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/media?parent=974"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/categories?post=974"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.materialstests.com\/sk\/wp-json\/wp\/v2\/tags?post=974"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}