{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-EBEUMPXW/ac069aac-8629-4c98-abd7-6cd3b8507d0c/PDF","dcterms:extent":"3094 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-EBEUMPXW/06fa3549-bdee-4044-a418-ce68d9d71ba2/TEXT","dcterms:extent":"0 KB"}],"edm:TimeSpan":{"@rdf:about":"1999-2026","edm:begin":{"@xml:lang":"en","#text":"1999"},"edm:end":{"@xml:lang":"en","#text":"2026"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:doc-EBEUMPXW","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/URN:NBN:SI:spr-6QOUKQ9A"},{"@xml:lang":"sl","#text":"Strojniški vestnik"}],"dcterms:issued":"2026","dc:creator":["Halilovič, Miroslav","Kotnik, Urban","Kutin, Jože","Oseli, Alen","Slemenik Perše, Lidija"],"dc:format":[{"@xml:lang":"sl","#text":"številka:1/2"},{"@xml:lang":"sl","#text":"letnik:72"},{"@xml:lang":"sl","#text":"str. 21-28"}],"dc:identifier":["ISSN:0039-2480","DOI:10.5545/sv-jme.2025.1548","COBISSID_HOST:272775939","URN:URN:NBN:SI:doc-EBEUMPXW"],"dc:language":"en","dc:publisher":[{"@xml:lang":"sl","#text":"= Association of Mechanical Engineers and Technicians of Slovenia etc."},{"@xml:lang":"sl","#text":"Zveza strojnih inženirjev in tehnikov Slovenije etc."}],"dc:subject":[{"@xml:lang":"en","#text":"creep tests"},{"@xml:lang":"en","#text":"measurement uncertainty"},{"@xml:lang":"sl","#text":"merilna negotovost"},{"@xml:lang":"sl","#text":"polimeri"},{"@xml:lang":"en","#text":"polimers"},{"@xml:lang":"sl","#text":"polipropilen"},{"@xml:lang":"en","#text":"polypropylene"},{"@xml:lang":"sl","#text":"preizkusi lezenja"},{"@xml:lang":"en","#text":"viscoelasticity"},{"@xml:lang":"sl","#text":"viskoelastičnost"}],"dcterms:temporal":{"@rdf:resource":"1999-2026"},"dc:title":{"@xml:lang":"sl","#text":"Evaluation of measurement uncertainty in creep-based determination of viscoelastic material functions of polypropylene|"},"dc:description":[{"@xml:lang":"sl","#text":"Modern numerical models use time-dependent material parameters as input data to simulate the viscoelastic response of polymers. Reliable numerical predictions therefore depend on the accurate determination of these parameters. Understanding the measurement uncertainty associated with their identification is essential for assessing the expected range and reliability of the simulation results. Although creep-based uncertainty analyses have been reported for other materials, uncertainty evaluations for polymers that require the determination of multiple viscoelastic material functions remain scarce, with existing polymer studies primarily relying on relaxation tests. This study experimentally analyzes the viscoelastic behavior of polypropylene at 60 °C through tensile and shear creep tests based on extensional and rotational rheometry. The tensile, shear, and bulk compliance functions were determined together with their corresponding standard and expanded measurement uncertainties in accordance with the JCGM 100:2008 guideline. Type A uncertainties were found to dominate the overall uncertainty, with relative expanded uncertainties of approximately 3 percent for shear compliance and up to 25 percent for bulk compliance. The study identifies the main sources of uncertainty and proposes strategies for their reduction, including increasing the number of measurement repetitions and improving environmental control. Overall, a comprehensive uncertainty evaluation of the creep-based determination of viscoelastic material functions is presented, leading to more reliable input data for numerical simulations"},{"@xml:lang":"sl","#text":"Sodobni numerični modeli uporabljajo časovno odvisne materialne parametre kot vhodne podatke za simulacijo viskoelastičnega odziva polimerov. Zanesljivost numeričnih napovedi je zato odvisna od točnosti določitve teh parametrov. Razumevanje merilne negotovosti, povezane z njihovo identifikacijo, je ključnega pomena za oceno pričakovanega razpona in zanesljivosti rezultatov simulacij. Čeprav so analize negotovosti na podlagi lezenja za druge materiale že znane, so vrednotenja negotovosti za polimere, ki zahtevajo določitev več viskoelastičnih materialnih funkcij, še vedno redka, obstoječe raziskave polimerov pa temeljijo predvsem na relaksacijskih preizkusih. Ta raziskava eksperimentalno analizira viskoelastično vedenje polipropilena pri 60 °C s pomočjo nateznih in strižnih preizkusov lezenja, ki temeljijo na natezni in rotacijski reometriji. Določene so bile natezna, strižna in stisljivostna podajnost ter pripadajoče standardne in razširjene merilne negotovosti v skladu s smernicami JCGM 100:2008. Rezultati kažejo, da negotovosti tipa A najbolj prispevajo k skupni standardni negotovosti, pri čemer so relativne razširjene negotovosti znašale približno 3 % za strižno podajnost in do 25 % za stisljivostno podajnost. Raziskava opredeljuje glavne vire negotovosti in predlaga strategije za njihovo zmanjšanje, vključno s povečanjem števila ponovitev meritev in izboljšanjem nadzora okoljskih pogojev. Predstavljeno je celovito vrednotenje negotovosti pri določanju viskoelastičnih materialnih funkcij na podlagi lezenja, kar zagotavlja zanesljivejše vhodne podatke za numerične simulacije"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"znanstveno časopisje"},{"@xml:lang":"en","#text":"journals"},{"@rdf:resource":"http://www.wikidata.org/entity/Q361785"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:doc-EBEUMPXW","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:doc-EBEUMPXW"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:doc-EBEUMPXW/ac069aac-8629-4c98-abd7-6cd3b8507d0c/PDF"},"edm:rights":{"@rdf:resource":"http://rightsstatements.org/vocab/InC/1.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Univerza v Ljubljani, Fakulteta za strojništvo"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:doc-EBEUMPXW/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:doc-EBEUMPXW"}}}}