{"?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-0LPGQKSI/870f6478-ea52-46d4-886f-2d023df89ea8/HTML","dcterms:extent":"14 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-0LPGQKSI/cd78b67b-7676-4f3d-9f88-2c666b02711d/PDF","dcterms:extent":"510 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-0LPGQKSI/c21cc96a-3a36-4eca-a4f9-989e3fe1b2e7/TEXT","dcterms:extent":"13 KB"}],"edm:TimeSpan":{"@rdf:about":"2000-2024","edm:begin":{"@xml:lang":"en","#text":"2000"},"edm:end":{"@xml:lang":"en","#text":"2024"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:DOC-0LPGQKSI","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/urn:nbn:si:spr-ihg6vo21"},{"@xml:lang":"sl","#text":"Materiali in tehnologije"}],"dcterms:issued":"2006","dc:creator":["Emri, Igor","Florjančič, Urška","Hribar, Anton","Kramar, Janez","Nikonov, Anatolij"],"dc:format":[{"@xml:lang":"sl","#text":"3 strani"},{"@xml:lang":"sl","#text":"letnik:40"},{"@xml:lang":"sl","#text":"številka:6"},{"@xml:lang":"sl","#text":"str. 239-242"}],"dc:identifier":["ISSN:1580-2949","COBISSID:578986","URN:URN:NBN:SI:doc-0LPGQKSI"],"dc:language":"en","dc:publisher":{"@xml:lang":"sl","#text":"Inštitut za kovinske materiale in tehnologije"},"dc:subject":[{"@xml:lang":"sl","#text":"deformacije"},{"@xml:lang":"sl","#text":"elastomeri"},{"@xml:lang":"sl","#text":"jermeni"},{"@xml:lang":"sl","#text":"utrujanje"},{"@xml:lang":"sl","#text":"viskoelastična analiza"},{"@rdf:resource":"http://www.wikidata.org/entity/Q252266"}],"dcterms:temporal":{"@rdf:resource":"2000-2024"},"dc:title":{"@xml:lang":"sl","#text":"Fatigue problems of transmission belts:| a viscoelastic analysis of the strain-accumulation process|"},"dc:description":[{"@xml:lang":"sl","#text":"We performed an analysis of the time-dependent behaviour of drive belts under the loading conditions to which they are exposed during normal operation. Theyare dynamically loaded with a tooth-like periodic (cyclic) load. Within each loading cycle the elastomeric material undergoes a combination of creep and retardation processes. Under certain conditions, the retardation process between two loadings cannot be fully completed. Thus, the material enters the second phase of loading with a residual strain state. Consequently, the strain state starts to accumulate, which leads to hardening of the material, crack formation, and ultimately to the failure of the belt. We recognized that drive belts exhibit the accumulation of strain when exposed to normal operation at certain critical angular velocities. The strain accumulated in each consecutive cycle depends on the geometry of the belt, the angular velocity of the pulleys, the number of completed cycles, and the retardation spectrum of the material. In this paper we discuss the effect of the number of loading cycles to which the material is exposed in the strain-accumulation process. For a given belt geometry the critical angular velocity increases with the number of loading cycles. At the same time the magnitude of the accumulated strain decreases non-linearly as the number of loading cycles increases. Hence, the strain-accumulation process slows down with the increasing number of loading cycles. However, if the belt operates at, or in the close vicinity of, its critical angular velocity, it will almost certainly fail. Since the critical angular velocity is directly related to the retardation time of the material, and the magnitude of the accumulated strain depends on the strength of the corresponding discrete spectrum lines, we can conclude that the time-dependent mechanical properties of the elastomersic material from which the belt is constructed are the most critical parameters for predicting the durability of drive belts and other dynamically loaded elastomeric products"},{"@xml:lang":"sl","#text":"V delu predstavljamo viskoelastično analizo časovno odvisnega vedenja pogonskih jermenov, ki so med obratovanjem motorja dinamično obremenjeni s koračno spremembo. V času enega obremenitvenega cikla je posamezna viskoelastična komponenta jermena izpostavljena kombiniranemu procesu lezenja in relaksacije. Pri določenih pogojih, ki jih opredeljujeta geometrija jermena in kotna hitrost jermenice, se proces retardacije med dvema obremenitvenima cikloma ne zaključi. To pomeni, da material vstopi v naslednjo obremenitveno fazo s preostalo deformacijo. Postopoma se začne deformacija akumulirati, kar vodi do utrjevanja materiala, nastanka razpoke in posledično do propada jermena. Analiza pokaže, da se akumulacija deformacije v jermenu pojavi pri določenih kritičnih vrednostih kotne hitrosti. Proces akumuliranja deformacije v vsakem zaporednem obremenitvenem ciklu je odvisen od geometrije jermena, kotne hitrosti jermenice, števila zaključenih obremenitvenih ciklov in retardacijskega spektra materiala, iz katerega je narejen jermen. Predstavljeno delo obravnava vpliv števila obremenitvenih ciklov na proces akumuliranja deformacije v pogonskem jermenu med obratovanjem motorja. Pri dani geometriji jermena kritična kotna hitrost narašča s povečevanjem števila obremenitvenih ciklov, medtem ko velikost akumulirane deformacije nelinearno pojema, kar kaže, da se z naraščanjem števila ciklov obremenjevanja proces akumuliranja deformacije upočasni. Rezultati kažejo, da bo jermen med obratovanjem pri kritični kotni hitrosti (oz. v njeni bližini) zelo verjetno odpovedal. Z ozirom na to, da je kritična kotna hitrost povezana z retardacijskim časom materiala in je velikost akumulirane deformacije odvisna od jakosti pripadajoče diskretne spektralne linije, lahko sklepamo, da so časovno odvisne mehanske lastnosti elastomernega materiala, iz katerega je narejen jermen, kritični parameter za napoved trajnosti jermenov in drugih dinamično obremenjenih elastomernih produktov"}],"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-0LPGQKSI","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:DOC-0LPGQKSI"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:DOC-0LPGQKSI/cd78b67b-7676-4f3d-9f88-2c666b02711d/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":"Inštitut za kovinske materiale in tehnologije"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:DOC-0LPGQKSI/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:DOC-0LPGQKSI"}}}}