20.500.12556/RUL-181202 Napoved mehanskega odziva spoja pri brizganih termoplastih, ojačanih s kratkimi vlakni Prediction of mechanical response of the weld line in injection-molded short fiber reinforced thermoplastics V delu obravnavamo modeliranje mehanskega odziva hladnih spojev pri polimerih, ojačanih s kratkimi vlakni, pri čemer se osredotočamo na dva vidika. Prvi je vpliv izbire aproksimacije v zaprti obliki na elastične lastnosti homogeniziranega kompozita, drugi pa modeliranje fenomenov prisotnih v hladnih spojih, ki vplivajo na degradacijo mehanskega obnašanja na teh mestih. V prvem delu smo s spreminjanjem aproksimacij izračunali elastične lastnosti kompozita na celotnem razponu možnih orentacijskih stanj in z analizo njihovih vrednosti prišli do ugotovitve, da izbira aproksimacije nima pomembnega vpliva. V drugem delu pa z nadgradnjo numeričnega modela iz literature z uporabo začetne poškodovanosti in njene evolucije na mestu spoja pokazali, da je tako mogoče opisati omenjene fenomene in ustrezno modelirati mehansko obnašanje na tem mestu. This work addresses the modeling of the mechanical response of cold joints in polymers reinforced with short fibers, focusing on two key aspects. The first concerns the influence of the choice of closure approximation on the elastic properties of the homogenized composite, while the second pertains to the modeling of phenomena present in cold joints that contribute to the degradation of mechanical behavior at these locations. In the first part, we computed the elastic properties of the composite across the full range of possible orientation states by varying the approximations, and through analysis of the resulting values, we found that the choice of approximation has no significant impact. In the second part, we extended a numerical model from the literature by incorporating initial damage and its evolution at the joint interface, demonstrating that this approach enables the description of the aforementioned phenomena and provides an adequate model of the mechanical behavior at the joint. brizgani termoplasti kompoziti ojačani s kratkimi vlakni hladni spoji mehanski odziv porazdelitvena funkcija usmerjenosti vlaken orientacijsko povprečenje aproksimacije v zaprti obliki konstitutivno modeliranje poškodovanost injection-molded thermoplastics short fibre reinforced polymer cold welds mechanical response fibre orientation distribution function orientation averaging closure approximation constitutive modelling damage true false false [M. Nabergoj] Slovenski jezik Neznan jezik Doktorsko delo/naloga 2026-03-27 08:30:25 2026-03-27 08:30:31 2026-03-31 09:10:36 0000-00-00 00:00:00 2026 0 Ljubljana 0 XXVI, 110 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 620.168:678.073:621.792(043.3) 283391 273657347 46615.pdf 46615.pdf 1 88827CFEF4830744D394B347E6BA4386 1d74c47d6cb3bf125addadddd88049bf16e6725f9b70a49b42736f02625ad963 b38ebffb-29ae-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=231426 Fakulteta za strojništvo 0 0 0