20.500.12556/DKUM-50448 Behaviour of short cracks emanating from tiny drilled holes Vedenje kratkih razpok, ki nastanejo iz majhnih izvrtin Specimens with martensitic microstructure were defected by tiny drilled holes with the existing local residual stresses induced by drilling and without them. The objective of this research was to determine the cyclic stress level for the crack initiation and fatigue limit of the defected and smooth specimens' dependence upon the residual-stress field. Compressive residual stresses retarded the crack initiation. Immediately after the crack initiation, residual stresses decelerated the short-crack propagation, but later, when the residual-stress sign was changed, they accelerated it. Non-propagating short-crack size and fatigue limit also depend on the residual-stress field. Pri preizkušancih z martenzitno mikrostrukturo smo naredili majhne izvrtine z obstoječimi lokalnimi zaostalimi napetostmi zaradi vrtanja in brez njih. Namen te raziskave je bilo določiti odvisnost ciklične napetosti, ki je potrebna za nastanek razpoke, in odvisnost trajne dinamične trdnosti z izvrtino oslabljenih in gladkih preizkušancev, od polja zaostalih napetosti. Tlačne zaostale napetosti so zavrle nastanek razpoke. Takoj po nastanku razpoke so zaostale napetosti upočasnile širjenje kratke razpoke, pozneje, ko se je predznak napetosti spremenil, pa so ga pospešile. Velikost kratke razpoke, ki se ne širi več, in trajna dinamična trdnost sta prav tako odvisni od polja zaostalih napetosti. small defect drilled hole crack initiation crack propagation short crack long crack anomalous fast-crack propagation majhne napake izvrtina nastanek razpoke širjenje razpoke kratka razpoka dolga razpoka nenormalno hitro širjenje razpoke true false true Angleški jezik Slovenski jezik Znanstveno delo 2015-07-10 12:40:03 2015-07-10 12:40:03 2022-05-29 03:07:02 2021-05-09 03:29:09 2013 0 0 str. 441-446 št. 4 Letn. 47 jul.-avg. 2013 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1580-2949 621.7.019.1 106193664 17043478 1580-2949 URN:SI:UM:DK:IDEJ2OKT Materiali_in_Tehnologije_2013_Gliha,_Maruschak,_Vuherer_Behaviour_of_Short_Cracks_Emanating_From_Tiny_Drilled_Holes.pdf Materiali_in_Tehnologije_2013_Gliha,_Maruschak,_Vuherer_Behaviour_of_Short_Cracks_Emanating_From_Tiny_Drilled_Holes.pdf 1 0C2F9B3D9A7162760B0309504CEC7C60 01ce7d4bce899d8c3b481db1369867bed668ac87eee722575e126f776705a021 fc11352a-7c0d-11eb-bb7a-00155d0001ca https://dk.um.si/Dokument.php?lang=slv&id=109787 http://mit.imt.si/Revija/izvodi/mit134/gliha.pdf 1 https://dk.um.si/Dokument.php?lang=slv&id=75007 Fakulteta za strojništvo 0 0 0