20.500.12556/RUL-92956 Določitev parametrov triaksialnosti aluminijeve zlitine za gnetenje Determination of parameters of stress triaxiality for aluminium wrought alloy Postopki preoblikovanja predstavljajo pomemben segment industrijske proizvodnje. Največkrat preoblikovalni procesi potekajo pri pogojih večosnega napetostnega stanja. Zaradi večosnega napetostnega stanja je pomembno poznavanje napetostne triaksialnosti, ki pogojuje pojav duktilnega loma. Dandanes se pri načrtovanju preoblikovanja izdelkov pogosto uporablja analiza v digitalnem okolju. V ta namen je potrebno poznati materialne parametre, s katerimi so povezani modeli duktilnega loma v računalniških programih. Eden izmed najpogosteje uporabljenih modelov, ki zajema parametre triaksialnosti in je implementiran v programu Abaqus, je Johnson-Cook-ov model. Za določitev parametrov triaksialnosti smo izvedli natezni preizkus paličastega aluminija AW 6082, pri katerem smo s pomočjo digitalne kamere opazovali spremembo geometrije. Iz zajetih slik smo izračunali napetostno triaksialnost. Na podlagi napetostne triaksialnosti in porušitvene deformacije smo določili Johnson-Cook-ove parametre triaksialnosti. V programu Abaqus smo na osnovi teh parametrov izvedli analizo natezne obremenitve preizkušanca z utorom in primerjali dobljene rezultate z vrednostmi iz eksperimenta. Metal forming processes play an important part in industrial manufacturing. In most cases metal forming processes are done under the conditions of multiaxial stress state. Due to this multiaxial stress state, it is important to have knowledge of stress triaxiality which is important for ductile fracture. Nowadays, analysis in digital environment is often used for planning a forming processes. Because of this, it is vital to know material parameters which are interfaced with ductile fracture in computer programs. One of the most frequently used models, which covers parameters of stress triaxiality and is implemented in Abaqus, is Johnson-Cook model. To determine stress triaxiality parameters we performed a tensile test of aluminium AW 6082 specimen. We used a digital camera to observe changes in geometry during tensile test. From the captured images we were able to calculate stress triaxiality. Based on stress triaxiality and strain at fracture we were able to determine Johnson-Cook triaxiality parameters. And these parameters allowed us to perform the simulation of the tensile test of a notched specimen and compare the results obtained with the values from the experiment. preoblikovanje kovin napetostna triaksialnost aluminij AW 6082 Johnson-Cook-ov model parametri triaksialnosti simulacija metal forming stress triaxiality aluminium AW 6082 Johnson-Cook model stress triaxiality parameters simulation true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2017-07-11 09:22:48 2017-07-11 09:22:49 2023-11-10 12:48:38 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 189595 485.pdf 485.pdf 1 FD70D12FBA0ED2C46105A9837E4572BF 385da1101634aab919077cf78cbc9389799a47029895c0b30c47658e61e14d82 77947bb9-a1b3-11eb-a523-00155dcfd717 20.500.12556/rul/57711ee0-d764-49c2-ba3c-6289553e00e3 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=101123 Fakulteta za strojništvo 0 0 0