CALIBRATION OF A NEW METHOD FOR CREATING IMPERFECTIONS ON SLENDER STRUCTURES : magistrsko deloSimon Hudales
, 2022, magistrsko delo
Opis: 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.
Ključne besede: stability analysis, initial geometric imperfections, thin-walled structures, finite element method
Objavljeno v DKUM: 06.07.2022; Ogledov: 250; Prenosov: 42
Celotno besedilo (5,14 MB)