20.500.12556/DKUM-81847 CALIBRATION OF A NEW METHOD FOR CREATING IMPERFECTIONS ON SLENDER STRUCTURES magistrsko delo UMERJANJE NOVE METODE ZA USTVARJANJE NEPOPOLNOSTI NA VITKIH STRUKTURAH For the design of slender structures consisting of plates and tubes, such as supporting structures at cranes, buckling is beside stress and fatigue often the governing failure criteria. Stability analysis of such structures is usually performed using the GMNIA method according to DIN EN 1993. For this purpose, a suitable geometric equivalent imperfection must be applied to the structure. Buckling inherent shapes are determined for this purpose and scaled according to applicable safety concepts. Including imperfections in stability analysis can generally be relevant for the load-bearing behavior of a structure. Within this master thesis work, the influence of the initial geometric imperfection on stability behaviour is investigated. This study examines the influence, that imperfections imposed on members subjected to tensile stress have on stability behaviour. Tensile members of structures are identified and initial geometric imperfection is imposed on them in addition to critical members, that are subjected to compression stress. It is shown, that including imperfections on tensile members in stability analysis, has only a minor influence on stability behaviour and stiffness of the structure, both reducing it just slightly. Further on, investigation on boom model, that is supporting structure of the crawler crane, is made. Boom model consist of main chord members and diagonals connecting them. At the joint connection of boom and two diagonal members, one subjected to tension and one subjected to compression stress, appears area of high shear stresses. Influence of the direction, that imperfection is imposed on the diagonal member, and what is the influence on the stability behaviour and structural strength is presented in this work. Most severe case of the two chosen direction is pointed out and discussed. Pri načrtovanju vitkih konstrukcij, sestavljenih iz plošč in cevi, kot so žerjavi, sta pogosto odločilni merili porušitve upogibanje in upogib. Stabilnostna analiza takšnih konstrukcij se običajno izvaja z metodo GMNIA v skladu z DIN EN 1993. V ta namenje treba na konstrukciji uporabiti ustrezno geometrijsko ekvivalentno nepopolnost. V ta namen se določijo inherentne oblike izbočenja, ki se skalirajo v skladu z veljavnimi varnostnimi koncepti. Vključitev nepopolnosti v stabilnostno analizo je lahko na splošno pomembna za obnašanje nosilne konstrukcije. V tem magistrskem delu je raziskan vpliv začetne geometrijske nepopolnosti na stabilnostno obnašanje. V tej študiji se preučuje vpliv, ki ga imajo nepopolnosti na elementih, izpostavljenih natezni obremenitvi, na stabilnostno obnašanje. Opredeljeni so natezni elementi konstrukcij, na katere se poleg kritičnih elementov, ki so izpostavljeni tlačni obremenitvi, definirajo začetne geometrijske nepopolnosti. Pokazalo se je, da vključitev nepopolnostina nateznih elementih pri analizi stabilnosti vpliva na stabilno obnašanje, saj se togost opazovane konstrukcije zmanjša. Oblike lastnih oblik izbočenja, pridobljene z linearno analizo izbočenja, nimajo opredeljene najhujše usmeritve. V tej študiji je bila opravljena preiskava na nateznih elementih podpornih konstrukcij. V ta namen je bila izvedena študija primera z različnimi koti med glavnim in ojačitvenim elementom. Ugotovljeno je bilo, da različne nastavitve kota med glavnim in ojačitvenim elementom nimajo bistvenega vpliva na stabilnostno obnašanje, čeprav vplivajo na trdnost konstrukcije. stability analysis initial geometric imperfections thin-walled structures finite element method analiza stabilnosti geometrijske nepravilnosti vitke konstrukcije metoda končnih elementov true true false [S. Hudales] Angleški jezik Slovenski jezik Magistrsko delo/naloga 2022-06-08 11:23:09 2022-07-06 12:13:08 2023-05-09 03:14:35 0000-00-00 00:00:00 2022 0 Maribor 0 Maribor 1 elektronski vir (1 datoteka PDF (XIVI, 71 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 62-237:620.179.7(043.2) 151258371 MAG_Hudales_Simon_2022.pdf MAG_Hudales_Simon_2022.pdf 1 E66802517AFCCBB3D6066857ACC4DC3F 7b6261867a8a6d59fc3f21d47b71b6c766963bca66b91843d20a38e916d5356d d6e4b625-eaef-11ec-8e53-00155d000105 20.500.12556/dkum/61cfe961-9772-4b5b-8737-f48f8ce7e683 https://dk.um.si/Dokument.php?lang=slv&id=158497 Fakulteta za strojništvo 0 0 0