20.500.12556/RUL-94432 Primerjava izračuna poškodbe zaradi utrujanja z energijskimi modeli Comparison of the calculation of damage due to fatigue with energy models Pri uporabi različnih metod določanja dobe trajanja, oziroma metod za izračun poškodb materiala v določenem obremenitvenem ciklu, je potrebno izhajati iz eksperimentalno pridobljenih podatkov za določeni material. Z namenom proučitve različnih metod in njihove primerjave z uveljavljenimi napetostnimi in deformacijskimi metodami, smo v okviru magistrskega dela obravnavali energijske modele izračuna poškodbe in jih primerjali z napetostnimi in deformacijskimi modeli. Dodatno smo medsebojno primerjali več korekcij srednjega nivoja napetosti, katere so formulirane na nivoju histerezne energije. Sledila je simulacija napetostno-deformacijskega stanja za izbrane obremenitvene cikle in izračun poškodbe. Za oceno učinkovitosti energijskih modelov smo dodatno obravnavali viskoplastične modele, ki so namenjeni korekciji vpliva časovne komponente na utrujanje gradiva. S postopkom vrednotenja energijskega poškodbenega parametra smo pričeli na podlagi pridobljenih eksperimentalnih podatkov meritev dob trajanja, ki so dostopni v objavljeni strokovni literaturi. Sledila sta določevanje parametrov modelov in izračun dob trajanja za posamezni model oziroma korekcijo. Ugotovili smo, da je pri uporabi energijskih modelov prisoten potencial, ker smo dobili primerljive rezultate z deformacijskimi modeli, v določenih primerih pa so rezultati bili celo bolj točni in z manj raztrosa. When using different fatigue life estimation methods or fatigue damage estimation methods for a given load cycle, the experimental data for a given material must be acquired first. In this master's thesis we discussed energy models for fatigue damage calculation and compared them with stress and strain models, with the purpose of studying different methods and their comparisons with well-established stress and strain methods. In addition, we compared several mean stress corrections methods whose formulation is based on energy of closed hysteresis loop. Next we simulated stress strain states for the selected load cycles and calculated the corresponding fatigue damage. Additionally we discussed viscoplastic models that include the effects of time component on the fatigue life to further evaluate the efficiency of energy models. We started the process of evaluating energy models on the basis of obtained experimental data of fatigue life measurements, which is available in the published literature. Next we calculated all model parameters and estimations of fatigue life for each discussed model and correction. We have found potential in usage of energy models, due to comparable results with strain models, and in certain cases the results were even more accurate and with less scatter. energijski modeli doba trajanja poškodba energija zaključene histerezne zanke cikel ciklično obremenjevanje poškodbeni parameter energy models fatigue life damage energy of closed hysteresis loop cycle cyclic loading damage parameter true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2017-08-25 07:15:39 2017-08-25 07:15:41 2023-12-13 11:20:38 0000-00-00 00:00:00 2017 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 194558 615.pdf 615.pdf 1 DD3EC67349AA43049E76B5166D5D5BCA 8420e476911f5a953e27e9a3d584b795fedd2c24809e4726e04e257b7a8b94ac 854ddcb0-a1b3-11eb-a523-00155dcfd717 20.500.12556/rul/6cf52018-56ac-4889-841c-97659b6e8f06 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=102650 Fakulteta za strojništvo 0 0 0