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41	Phase-field modeling of brittle fracture along the thickness direction of plates and shells Ambati, Marreddy, Heinzmann, Jonas, Seiler, Martha, Kästner, Markus 22 January 2024 (has links) The prediction of fracture in thin-walled structures is decisive for a wide range of applications. Modeling methods such as the phase-field method usually consider cracks to be constant over the thickness which, especially in load cases involving bending, is an imperfect approximation. In this contribution, fracture phenomena along the thickness direction of structural elements (plates or shells) are addressed with a phase-field modeling approach. For this purpose, a new, so called “mixed-dimensional” model is introduced, which combines structural elements representing the displacement field in the two-dimensional shell midsurface with continuum elements describing a crack phase-field in the three-dimensional solid space. The proposed model uses two separate finite element discretizations, where the transfer of variables between the coupled twoand three-dimensional fields is performed at the integration points which in turn need to have corresponding geometric locations. The governing equations of the proposed mixed-dimensional model are deduced in a consistent manner from a total energy functional with them also being compared to existing standard models. The resulting model has the advantage of a reduced computational effort due to the structural elements while still being able to accurately model arbitrary through-thickness crack evolutions as well as partly along the thickness broken shells due to the continuum elements. Amongst others, the higher accuracy aswell as the numerical efficiency of the proposed model are tested and validated by comparing simulation results of the new model to those obtained by standard models using numerous representative examples. info:eu-repo/classification/ddc/510 ddc:510
42	Wachstumsanalyse amorpher dicker Schichten und Schichtsysteme / Growth analysis of thick amorphous films and multilayers Streng, Christoph 18 May 2004 (has links) No description available. Mathematics and Computer Science Dünne Schichten dicke Schichten Multilagen UHV Elektronenstrahlverdampfen metallische Gläser Rastertunnelmikroskopie Rasterkraftmikroskopie Oberflächenmorphologie diffuse Röntgenstreuung Röntgenreflektivität Molekulardynamiksimulation Kontinuumsmodell 530 Physik Thin films thick films multilayers UHV electron beam evaporation metallic glasses scanning tunneling microscopy scanning force microscopy surface morphology diffuse X-ray scattering X-ray reflection molecular dynamics simulation continuum model stochastic partial differential equation 33.66 33.68
43	Wachstumsanalyse amorpher dicker Schichten und Schichtsysteme / Growth analysis of thick amorphous films and multilayers Streng, Christoph 18 May 2004 (has links) No description available. Mathematics and Computer Science Dünne Schichten dicke Schichten Multilagen UHV Elektronenstrahlverdampfen metallische Gläser Rastertunnelmikroskopie Rasterkraftmikroskopie Oberflächenmorphologie diffuse Röntgenstreuung Röntgenreflektivität Molekulardynamiksimulation Kontinuumsmodell 530 Physik Thin films thick films multilayers UHV electron beam evaporation metallic glasses scanning tunneling microscopy scanning force microscopy surface morphology diffuse X-ray scattering X-ray reflection molecular dynamics simulation continuum model stochastic partial differential equation 33.66 33.68

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