{"id":2177,"date":"2017-05-02T09:24:22","date_gmt":"2017-05-02T09:24:22","guid":{"rendered":"https:\/\/www.tudc.cz\/?page_id=2177"},"modified":"2024-05-10T14:21:27","modified_gmt":"2024-05-10T12:21:27","slug":"wpgnt","status":"publish","type":"page","link":"https:\/\/www.tudc.cz\/index.php\/diagnosticke-prostredky\/wpgnt\/","title":{"rendered":"Zku\u0161ebn\u00ed syst\u00e9m WPG NT pro m\u011b\u0159en\u00ed metodou v\u00ed\u0159iv\u00fdch proud\u016f"},"content":{"rendered":"\n

Zku\u0161ebn\u00ed syst\u00e9m WPG NT pro m\u011b\u0159en\u00ed metodou v\u00ed\u0159iv\u00fdch proud\u016f<\/h1>\n\n\n

\"\"<\/a>V souladu s v\u00fdvojem trend\u016f vyu\u017e\u00edvan\u00fdch metod nedestruktivn\u00edho testov\u00e1n\u00ed (NDT) pro kontrolu kolejnic za\u010dala Spr\u00e1va \u017eeleznic, st\u00e1tn\u00ed organizace, pou\u017e\u00edvat za\u0159\u00edzen\u00ed a p\u0159\u00edstroje pracuj\u00edc\u00ed na principu m\u011b\u0159en\u00ed pomoc\u00ed v\u00ed\u0159iv\u00fdch proud\u016f (ET – Eddy current).<\/p>\n

Syst\u00e9m m\u011b\u0159en\u00ed pomoc\u00ed ET je u CTD prim\u00e1rn\u011b optimalizov\u00e1n pro detekci a vyhodnocen\u00ed kontaktn\u011b \u00fanavov\u00e9 vady Head Checking, kter\u00e1 se rozv\u00edj\u00ed na poj\u00ed\u017ed\u011bn\u00e9 hran\u011b a poj\u00ed\u017ed\u011bn\u00fdch ploch\u00e1ch kolejnic. D\u016fraz je kladen na ur\u010den\u00ed v\u00fdskytu t\u011bchto vad a d\u00e1le hloubky trhlin tak, aby bylo mo\u017eno efektivn\u011b prov\u00e9st jejich odstran\u011bn\u00ed. Sekund\u00e1rn\u011b jsou p\u0159i m\u011b\u0159en\u00ed zachyceny tak\u00e9 dal\u0161\u00ed projevy po\u0161kozen\u00ed povrchu materi\u00e1lu, jako jsou zn\u00e1mky obrou\u0161en\u00ed a prohlubn\u00ed nebo dal\u0161\u00ed vady dle p\u0159edpisu S\u017d S3\/7. Hodnocen\u00ed vad Head Checking se prov\u00e1d\u00ed a\u017e do hloubky po\u0161kozen\u00ed 2,7 mm (vypo\u010dteno pod \u00fahlem 25\u00b0).<\/p>\n

Zkou\u0161en\u00ed nedestruktivn\u00ed metodou v\u00ed\u0159iv\u00fdch proud\u016f<\/h6>\n

Metoda v\u00ed\u0159iv\u00fdch proud\u016f (ET) se u\u017e\u00edv\u00e1 ke zkou\u0161en\u00ed elektricky vodiv\u00fdch materi\u00e1l\u016f, kter\u00e9 mohou b\u00fdt feromagnetick\u00e9 i neferomagnetick\u00e9. Metoda pat\u0159\u00ed mezi tzv. povrchov\u00e9 metody, to znamen\u00e1, \u017ee je nej\u010dast\u011bji pou\u017e\u00edv\u00e1na k hled\u00e1n\u00ed povrchov\u00fdch vad. V z\u00e1vislosti na pou\u017eit\u00e9 frekvenci a druhu zkou\u0161en\u00e9ho materi\u00e1lu ji lze v\u0161ak vyu\u017e\u00edt i pro vyhled\u00e1v\u00e1n\u00ed vad v ur\u010dit\u00e9 hloubce pod povrchem. U Spr\u00e1vy \u017eeleznic, st\u00e1tn\u00ed organizace, je pou\u017e\u00edv\u00e1na k vyhled\u00e1v\u00e1n\u00ed povrchov\u00fdch vad kolejnic.<\/p>\n

Princip vzniku v\u00ed\u0159iv\u00fdch proud\u016f: Pokud se n\u011bjak\u00fd elektricky vodiv\u00fd materi\u00e1l dostane do bl\u00edzkosti elektrick\u00e9ho pole, pak se voln\u00e9 elektrony v tomto materi\u00e1lu daj\u00ed do pohybu. T\u00edm vznik\u00e1 elektrick\u00fd proud. V materi\u00e1lu tak vznik\u00e1 v\u00edce takov\u00fdch proudov\u00fdch obvod\u016f a tyto proudy naz\u00fdv\u00e1me proudy v\u00ed\u0159iv\u00fdmi.<\/p>\n\n\n\n\n
V\u00fdhody metody ET<\/strong>    \n

 <\/p>\n

 <\/p>\n

    \n
  • relativn\u011b levn\u00e1 kontrola v\u016f\u010di n\u011bkter\u00fdm jin\u00fdm, nap\u0159. proza\u0159ovac\u00edm metod\u00e1m<\/li>\n
  • mo\u017enost realizovat lehk\u00e9 p\u0159enosn\u00e9 p\u0159\u00edstroje pro NDT<\/li>\n
  • mo\u017enost automatizace kontroln\u00edho procesu<\/li>\n
  • zkou\u0161en\u00ed m\u016f\u017ee b\u00fdt bezkontaktn\u00ed nap\u0159. oproti UT<\/li>\n
  • net\u0159eba p\u0159ed kontrolou n\u011bjak speci\u00e1ln\u011b upravovat povrch<\/li>\n
  • mo\u017en\u00e1 vysok\u00e1 rychlost zkou\u0161en\u00ed<\/li>\n
  • umo\u017e\u0148uje m\u011b\u0159en\u00ed i p\u0159i vy\u0161\u0161\u00edch teplot\u00e1ch<\/li>\n<\/ul>\n<\/td>\n
Nev\u00fdhody metody ET<\/strong>    \n

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 <\/p>\n

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  • nen\u00ed mo\u017en\u00e9 indikovat vady hluboko pod povrchem (pouze do 10 – 25 mm)<\/li>\n
  • omezen\u00ed jen na materi\u00e1ly elektricky vodiv\u00e9<\/li>\n
  • zna\u010dn\u00e1 citlivost na rozm\u011bry zkou\u0161en\u00e9 sou\u010d\u00e1sti<\/li>\n
  • p\u0159i vzniku v\u00ed\u0159iv\u00fdch proud\u016f vznik\u00e1 oh\u0159ev materi\u00e1lu vlivem ohmick\u00fdch ztr\u00e1t<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n
 \"\"<\/a><\/td>\n  \"\"<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

V \u010dervenci roku 2015 S\u017dDC T\u00daDC (dnes S\u017d CTD) p\u0159evzala v r\u00e1mci Projektu p\u0159estavby Diagnostick\u00e9 soupravy NDT ru\u010dn\u00ed syst\u00e9m kontroly v\u00ed\u0159iv\u00fdch proud\u016f WPG NT od spole\u010dnosti PLR Pr\u00fcftechnik Linke & R\u00fche GmbH\u00ae, spl\u0148uj\u00edc\u00ed technickou normu DIN EN ISO 15548. P\u0159edpokl\u00e1d\u00e1 se, \u017ee pr\u00e1v\u011b tento syst\u00e9m v kombinaci s nov\u011b po\u0159izovanou Diagnostickou jednotkou NDT zajist\u00ed rozhoduj\u00edc\u00ed diagnostick\u00e1 m\u011b\u0159en\u00ed a hodnocen\u00ed stavu kolejnic pro pl\u00e1nov\u00e1n\u00ed v\u00fdkon\u016f brou\u0161en\u00ed na kolej\u00edch Spr\u00e1vy \u017eeleznic, st\u00e1tn\u00ed organizace. Kvalitn\u00ed diagnostika stavu kolejnic je p\u0159itom d\u016fle\u017eit\u00e1 nejen pro pl\u00e1nov\u00e1n\u00ed m\u00edst a rozsahu opravn\u00fdch prac\u00ed, ale i pro dosa\u017een\u00ed optim\u00e1ln\u00ed ceny a v\u00fdlukov\u00e9 n\u00e1ro\u010dnosti t\u011bchto prac\u00ed.<\/p>\n

Odd\u011blen\u00ed NDT \u017eelezni\u010dn\u00edho svr\u0161ku Technick\u00e9 \u00fast\u0159edny dopravn\u00ed cesty, kter\u00e9 z\u00e1rove\u0148 pln\u00ed funkci Hlavn\u00edho defektoskopick\u00e9ho st\u0159ediska Spr\u00e1vy \u017eeleznic, st\u00e1tn\u00ed organizace, krom\u011b tohoto zku\u0161ebn\u00edho syst\u00e9mu ji\u017e vlastn\u00ed i dal\u0161\u00ed p\u0159\u00edstroje, zalo\u017een\u00e9 na m\u011b\u0159en\u00ed pomoc\u00ed v\u00ed\u0159iv\u00fdch proud\u016f. Ru\u010dn\u00ed p\u0159\u00edstroje spolu s r\u016fzn\u00fdmi typy sn\u00edma\u010d\u016f mohou naj\u00edt uplatn\u011bn\u00ed nap\u0159\u00edklad tam, kde je nevhodn\u00e9 z \u010dasov\u00e9ho \u010di jin\u00e9ho d\u016fvodu pou\u017eit\u00ed jin\u00fdch metod NDT.<\/p>\n

Z\u00e1kladn\u00ed sou\u010d\u00e1sti zku\u0161ebn\u00edho syst\u00e9mu WPG NT:<\/strong><\/p>\n