Accurate computational representations of highly deformable surfaces are indispensable in the fields of computer animation, medical simulation, computer vision, digital modeling, and computational physics. The focus of this dissertation is on the animation of physics-based phenomena with highly detailed deformable surfaces represented by triangle meshes. We first present results from an algorithm that generates continuum mechanics animations with intricate surface features. This method combines a finite element method with a tetrahedral mesh generator and a high resolution surface mesh, and it is orders of magnitude more efficient than previous approaches. Next, we present an efficient solution for the challenging problem of computing topological changes in detailed dynamic surface meshes. We then introduce a new physics-inspired surface tracking algorithm that is capable of preserving arbitrarily thin features and reproducing realistic fine-scale topological changes like Rayleigh-Plateau instabilities. This physics-inspired surface tracking technique also opens the door for a unique coupling between surficial finite element methods and volumetric finite difference methods, in order to simulate liquid surface tension phenomena more efficiently than any previous method. Due to its dramatic increase in computational resolution and efficiency, this method yielded the first computer simulations of a fully developed crown splash with droplet pinch off.

SILVA, Carlos Alex Souza da. Espaços Fuzzy e aspectos quânticos dos buracos negros. 2011. 90 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2011. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-05-19T18:59:25Z No. of bitstreams: 1 2011_tese_cassilva.pdf: 1020582 bytes, checksum: 1b31f01769f35ca43fcda25a0b345393 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-05-22T20:03:22Z (GMT) No. of bitstreams: 1 2011_tese_cassilva.pdf: 1020582 bytes, checksum: 1b31f01769f35ca43fcda25a0b345393 (MD5) / Made available in DSpace on 2015-05-22T20:03:22Z (GMT). No. of bitstreams: 1 2011_tese_cassilva.pdf: 1020582 bytes, checksum: 1b31f01769f35ca43fcda25a0b345393 (MD5) Previous issue date: 2011 / A model based on the topology change of a quantum manifold is used to explain the origin of the black hole thermodynamics. Some important issues are addressed, for example, why black holes obey a generalized second law of thermodynamics. The method we use to do this is to analyze the selection rules for black hole area transitions in the evaporation process driven by topology change. A discrete spectrum, which becomes increasingly spaced as the black hole approaches the Planck scale, is obtained for the black hole area. The black hole information loss paradox is also addressed. / Propomos um modelo baseado na mudança de topologia de uma variedade quântica no sentido de justificar a origem da termodinâmica dos buracos negros. Alguns pontos importantes são discutidos, por exemplo, o porquê de os buracos negros obedecerem a uma segunda lei generalizada da termodinâmica. Para isso, nós estudamos as regras de seleção que governam as transições de área de um buraco negro durante o seu processo de evaporação, sendo estas governadas pelo processo de mudança de topologia. Obtemos um espectro discreto para a área do horizonte de eventos, o qual se torna cada vez mais espaçado à medida que o buraco negro aproxima da escala de Planck. O paradoxo da perda de informação por buracos negros é, também, discutido.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Propomos um modelo baseado na mudanÃa de topologia de uma variedade quÃntica no sentido de justificar a origem da termodinÃmica dos buracos negros. Alguns pontos importantes sÃo discutidos, por exemplo, o porquà de os buracos negros obedecerem a uma segunda lei generalizada da termodinÃmica. Para isso, nÃs estudamos as regras de seleÃÃo que governam as transiÃÃes de Ãrea de um buraco negro durante o seu processo de evaporaÃÃo, sendo estas governadas pelo processo de mudanÃa de topologia. Obtemos um espectro discreto para a Ãrea do horizonte de eventos, o qual se torna cada vez mais espaÃado à medida que o buraco negro aproxima da escala de Planck. O paradoxo da perda de informaÃÃo por buracos negros Ã, tambÃm, discutido. / A model based on the topology change of a quantum manifold is used to explain the origin of the black hole thermodynamics. Some important issues are addressed, for example, why black holes obey a generalized second law of thermodynamics. The method we use to do this is to analyze the selection rules for black hole area transitions in the evaporation process driven by topology change. A discrete spectrum, which becomes increasingly spaced as the black hole approaches the Planck scale, is obtained for the black hole area. The black hole information loss paradox is also addressed.

This thesis investigates the effects of damage characteristics on residual compressive strength (RCS) of 4-mm thick preconditioned carbon/epoxy quasi-isotropic panels through the study of their compressive behaviour. Results of 2-mm thick preconditioned panels mostly from a previous study are also analysed. The preconditions of varying sizes include impact damage, quasi-static damage, single and multiple artificial delaminations of circular and elliptical shapes embedded at different through-the-thickness (TTT) locations, hemispherical-shaped domes of different curvature and depth and open holes. The mechanisms of impact damage and the characteristics of energy absorption were dependent on panel thickness and incident kinetic energy (IKE). A damage threshold for compressive strength (CS) reduction was found at 455-mm2 and 1257 mm2 for 2- and 4-mm thick panels, respectively. Panels affected by the presence of internal delaminations followed a sequence of prebuckling, local and global buckling (mode I) and postbuckling (mode II) in both the longitudinal and transverse directions. Their compressive failure was related to mode I to II transition. Possibility of delamination propagation was examined using response characteristics on the basis of the sequences. Evidence of delamination propagation was found only in panels with large damages and was not sensitive to RCS. For low and intermediate IKEs the effect of impact damage could be simulated with a single delamination (2-mm thick panels) and 3 delaminations of medium size (4-mm thick panels). For high IKEs, the additional effect of local curvature change was significant. The combined effect of delamination number, size and curvature change determines the RCSs. It was demonstrated that the present method of embedding artificial delaminations proves to be very useful for studying RCS of impact-damaged panels via the establishment of response characteristics and their links to the effects of the preconditions on them. This thesis also presents two analytical models, one for deflection of transversely loaded panels and the other one for the prediction of compressive strength retention factor (CSRF) based on the correlation between the ratio of maximum transverse force to initial threshold force and the CSRF, observed experimentally in thick panels.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第23677号 / 理博第4767号 / 新制||理||1683(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)准教授 SVADLENKA Karel, 教授 泉 正己, 教授 坂上 貴之 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM