20.500.12556/DKUM-53359 Preostala uporabnost kovičenega železniškega mostu The residual service life of the riveted railway bridge Opisano je določevanje preostale uporabnosti kovičenega jeklenega železniškega mostu čez Dravo na Ptuju. Izračun temelji na metodah mehanike loma, na integraciji Parisove funkcije. Za začetno velikost napake vzamemo hipotetično razpoko, ki je skrita pod glavo kovice, kritično velikost razpoke pa določimo z merjenjem kritične vrednosti J-integrala ter z uporabo znane Sedlackekove odvisnosti J proti a, pri čemer je a velikost razpoke. The residual service life of the riveted railway bridge across the Drava river near Ptuj is described. The calculation is based on fracture mechanics concepts, on the integration of Paris function. The hypothetical crack hidden under the heat of the rivet was considered as initial flaw, whereas the critical crack size was determined by measuring the critical value of J-integral and J vs. a relationship proposed by Sedlacek, where a is the crack size. Specimens were made from a steel lamella from a diagonal brace and the crack propagation rate and the fracture toughness of the steel were measured. All the measurements were performed at room temperature and at -20°C. the Paris function with threshold stress intensity range ▫$K_{th}$▫ was measured whereas the ▫$J_{lc}$▫ integral was estimated on the basis of the known ▫$K_{lc}$▫ values. Some of the ▫$J_{lc}$▫ were measured directly too. The results are given as a number of cycles which can provoke a critical cracklengthening and are a reliable base for determining the frequency of detectoscopic inspections of vital elements of the bridge. mehanika loma preostala uporabnost utrujanje kovičeni jekleni mostovi jeklene konstrukcije železne konstrukcije železniški mostovi riveted steel bridges fatigue residual service life fracture mechanics metal structures true true false Inštitut za kovinske materiale in tehnologije Slovenski jezik Neznan jezik Delo ni kategorizirano 2015-07-10 20:12:02 2015-07-10 20:12:02 2022-06-03 03:09:33 2019-07-11 08:08:03 1996 0 0 str. 455-462 št. 5 Letn. 30 1996 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 625.1:624.014.2 31742209 2505750 1318-0010 URN:SI:UM:DK:K5AGG7EV http://www.dlib.si/details/URN:NBN:SI:doc-NO15KTHA 1 https://dk.um.si/Dokument.php?lang=slv&id=77919 Fakulteta za strojništvo 0 0 0