20.500.12556/RUL-125611 Dinamske obremenitve vijačnih vzmeti Dynamic loads of helical springs Vijačne vzmeti se v hitrotekočih vratih uporablja kot akumulator mehanske energije, ki pripomore k hitremu odpiranju vratne plošče. Zaradi hitrega odpiranja in sunkovitih pomikov vzmeti nihajo, kar lahko vpliva na njihovo dobo trajanja. S pomočjo metode dinamske togosti so bile določene lastne frekvence obravnavane vzmeti. Sledila je določitev kritično obremenjenih mest na podlagi implicitne in harmonske analize. Z modificiranim Goodmanovim diagramom in Bergmannovo korekcijo je bila ocenjena doba trajanja za kritično obremenjena mesta na vzmeti. Rezultati so bili eksperimentalno preverjeni. Ugotovljeno je bilo, da odziv z lastnimi oblikami privede do višjih napetosti in krajše dobe trajanja v primerjavi s kvazi-statično obremenitvijo. Coil springs are used in high-speed doors as a mechanical energy accumulator, which contributes to a rapid opening of the door leaf. Due to the rapid opening and jerky movements, the springs oscillate, which can reduce their service life. Using the dynamic stiffness formulation, the natural frequencies of the considered spring were determined. This was followed by the identification of critically loaded points based on implicit and harmonic analysis. With a modified Goodman diagram and Bergmann correction, service life of critical points on the spring was estimated. The results were experimentally verified. It has been found that the response with natural frequency modes leads to higher stresses and shorter service life, if compared to the quasi-static case. vijačne vzmeti dinamske obremenitve dinamska togost implicitna analiza harmonska analiza modificiran Goodmanov diagram Bergmannova korekcija coil springs dynamic loads dynamic stiffness formulation implicit analysis harmonic analysis modified Goodman diagram Bergmann correction true false false [L. Bregar] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2021-03-27 08:30:40 2021-03-27 08:30:45 2022-09-05 03:51:36 0000-00-00 00:00:00 2021 0 Ljubljana 0 XXVIII, 79 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.826.22:531.3:620.172(043.2) 228320 58578947 6865.pdf 6865.pdf 1 EB108077B1294ECC1C64D1CBDFDCBE83 0de9d44b2190a746598bc4713b932f80e9b47e4c2f48047e4c84fc9fa95d3c07 be64291d-a1bb-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=141404 Fakulteta za strojništvo 0 0 0