Littérature scientifique sur le sujet « Formal deformations »
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Articles de revues sur le sujet "Formal deformations"
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Fialowski, Alice, et Michael Penkava. « On singular formal deformations ». Archiv der Mathematik 106, no 5 (12 mars 2016) : 431–38. http://dx.doi.org/10.1007/s00013-016-0894-2.
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Blanc, Anthony, Ludmil Katzarkov et Pranav Pandit. « Generators in formal deformations of categories ». Compositio Mathematica 154, no 10 (30 août 2018) : 2055–89. http://dx.doi.org/10.1112/s0010437x18007303.
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In this paper we use the theory of formal moduli problems developed by Lurie in order to study the space of formal deformations of a$k$-linear$\infty$-category for a field$k$. Our main result states that if${\mathcal{C}}$is a$k$-linear$\infty$-category which has a compact generator whose groups of self-extensions vanish for sufficiently high positive degrees, then every formal deformation of${\mathcal{C}}$has zero curvature and moreover admits a compact generator.
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Keller, Frank, et Stefan Waldmann. « Formal deformations of Dirac structures ». Journal of Geometry and Physics 57, no 3 (février 2007) : 1015–36. http://dx.doi.org/10.1016/j.geomphys.2006.08.005.
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Grinberg, M., et D. Kazhdan. « Versal deformations of formal arcs ». Geometric and Functional Analysis 10, no 3 (septembre 2000) : 543–55. http://dx.doi.org/10.1007/pl00001628.
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Huebschmann, Johannes. « The formal Kuranishi parameterization via the universal homological perturbation theory solution of the deformation equation ». Georgian Mathematical Journal 25, no 4 (1 décembre 2018) : 529–44. http://dx.doi.org/10.1515/gmj-2018-0054.
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AbstractUsing homological perturbation theory, we develop a formal version of the miniversal deformation associated with a deformation problem controlled by a differential graded Lie algebra over a field of characteristic zero. Our approach includes a formal version of the Kuranishi method in the theory of deformations of complex manifolds.
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BOURQUI, DAVID, et JULIEN SEBAG. « DEFORMATIONS OF DIFFERENTIAL ARCS ». Bulletin of the Australian Mathematical Society 94, no 3 (16 août 2016) : 405–10. http://dx.doi.org/10.1017/s0004972716000459.
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Let$k$be field of characteristic zero. Let$f\in k[X,Y]$be a nonconstant polynomial. We prove that the space of differential (formal) deformations of any formal general solution of the associated ordinary differential equation$f(y^{\prime },y)=0$is isomorphic to the formal disc$\text{Spf}(k[[Z]])$.
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Elhamdadi, Mohamed, et Abdenacer Makhlouf. « Cohomology and Formal Deformations of Alternative Algebras ». Journal of Generalized Lie Theory and Applications 5 (2011) : 1–10. http://dx.doi.org/10.4303/jglta/g110105.
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Chouhy, Sergio. « On geometric degenerations and Gerstenhaber formal deformations ». Bulletin of the London Mathematical Society 51, no 5 (24 juillet 2019) : 787–97. http://dx.doi.org/10.1112/blms.12277.
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Karabegov, Alexander. « Infinitesimal Deformations of a Formal Symplectic Groupoid ». Letters in Mathematical Physics 97, no 3 (10 mai 2011) : 279–301. http://dx.doi.org/10.1007/s11005-011-0495-8.
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DEMCHENKO, OLEG, et ALEXANDER GUREVICH. « GROUP ACTION ON THE DEFORMATIONS OF A FORMAL GROUP OVER THE RING OF WITT VECTORS ». Nagoya Mathematical Journal 235 (20 décembre 2017) : 42–57. http://dx.doi.org/10.1017/nmj.2017.43.
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A recent result by the authors gives an explicit construction for a universal deformation of a formal group $\unicode[STIX]{x1D6F7}$ of finite height over a finite field $k$ . This provides in particular a parametrization of the set of deformations of $\unicode[STIX]{x1D6F7}$ over the ring ${\mathcal{O}}$ of Witt vectors over $k$ . Another parametrization of the same set can be obtained through the Dieudonné theory. We find an explicit relation between these parameterizations. As a consequence, we obtain an explicit expression for the action of $\text{Aut}_{k}(\unicode[STIX]{x1D6F7})$ on the set of ${\mathcal{O}}$ -deformations of $\unicode[STIX]{x1D6F7}$ in the coordinate system defined by the universal deformation. This generalizes a formula of Gross and Hopkins and the authors’ result for one-dimensional formal groups.
Thèses sur le sujet "Formal deformations"
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Leitner, Frederick Carl. « Deformation Theory of Non-Commutative Formal Groups in Positive Characteristic ». Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1234%5F1%5Fm.pdf&type=application/pdf.
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Espath, Luis Felipe da Rosa. « Otimização de forma de cascas via deformação livre de forma baseado em NURBS ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/19043.
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Neste trabalho buscou-se consolidar a união entre três áreas do conhecimento: a parametrização de curvas e superfícies do tipo B-spline racionais não-uniformes (NURBS), a otimização matemática e a análise estrutural por elementos finitos. A união destas três áreas é realizada neste trabalho através da otimização de formas de cascas, devido ao fato de que as características mecânicas dos materiais devem refletir-se na forma da estrutura e sua distribuição de espessura expressando um máximo desempenho. Estas variáveis, forma e distribuição de espessura, possuem um rol dominante nos projetos de engenharia, já que mínimas quantidades de materiais, uma frequência específica, um estado puro de tensões de membrana são típicos objetivos de projeto. Neste contexto, obter a forma e a distribuição de espessura adequadas são conceitos intrínsecos à otimização estrutural. Portanto, implementaram-se técnicas para modificar a geometria de cascas, sem perder a parametrização, sem a necessidade de gerar uma nova malha de elementos finitos ao se modificar a forma e ainda ter controle sobre a distorção da malha para evitar erros numéricos inaceitáveis. A modificação de forma é fomentada pelo código de otimização, programação quadrática sequencial (SQP), motivado pelas análises da casca por elementos finitos. A modificação de forma é realizada pela técnica de deformação livre de forma (free-form deformation) com a parametrização NURBS. Nos resultados da otimização de formas de cascas obtiveram-se cascas com alto desempenho estrutural e esteticamente agradáveis.Consolidation of the link among three fields, curves and surfaces described by non-uniform rational B-spline (NURBS), mathematical optimization and finite element structural analysis, applied to shape optimization of shells, is the main objective of this work. Shape optimization of shells are performed taking into account the fact that the material mechanical caracteristics influence the structural shape and the thickness variation in order to obtain the best performace. These two variables, shape and thickness variation, have an essential role considering that the minimum material quantities, a specific frequency and a pure membrane stress state are typical design objectives. Suitable shapes and thickness variation are intrinsic concepts of structural optimization. Therefore, some techniques were implemented to modify the shell geometry conserving the same parameterization without a new finite element mesh generation and controlling mesh distortion in order to avoid relevant numerical errors. The shape modification is conducted by the optimization code and it is based in the data obtained by finite element analysis. In this work the optimization procedure is performed using a Sequential Quadratic Programming (SQP) algorithm, while the shape modification is carried out by the freeform deformation technique, based on NURBS parameterization. As a consequence of the shape optimization, shells with high structural performance and esthetically beautiful were obtained.
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Hurle, Benedikt. « Deformation and Quantization of color Lie bialgebras and alpha-type cohomologies for Hom-algebras ». Thesis, Mulhouse, 2018. http://www.theses.fr/2018MULH1819/document.
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La première partie de la thèse traite des déformations et quantification de bialgèbres de Lie. L'existence d'une quantification pour chaque bialgèbre de Lie a été démontrée par Etingof et Kazhdan. Dans ce travail, on s'intéresse au cas des bialgèbres de Lie colorée, c'est à dire une structure de bialgèbres de Lie sur un espace gradué par un groupe quelconque et un bicaractère. A cet effet, on adapte la preuve de Etingof et Kazhdan et on introduit une généralisation au cas coloré du grand crochet introduit par Lecomte et Roger. Par ailleurs nous définissons une cohomologie pour les algèbres et bialgèbres de Lie colorées. Dans le deuxième partie de la thèse, on considère les algèbres Hom-associatives et algèbres Hom-Lie. Une algèbre Hom-associative est définie par une multiplication et une application linéaire alpha modifiant l'associativité. On commence cette partie par rappeler des définitions et propriétés des algèbres de type Hom. Ensuite, on définit la cohomologie de Hochschild de type alpha, en donnant ses propriétés. Une étude similaire est faite dans le cas des algèbres Hom-Lie et la cohomologie de Chevalley-Eilenberg, ainsi que pour les Hom-bialgèbres et bialgèbres Hom-Lie. La théorie de déformations formelles introduite par Gerstenhaber met en lien les déformations et la cohomologie. Dans cette thèse on établit une théorie de déformations des algèbres Hom-associatives basée sur la cohomologie de Hochschild de type alpha. Il s'agit de déformer simultanément la multiplication et l'application linéaire. Par ailleurs, on explore la structure d’algèbre de Lie à homotopie près correspondante, telle que les éléments de Maurer-Cartan sont des Hom-algèbresIn the first part of this thesis, we provide a proof that any color Lie bialgebra can be quantized. This was proved for Lie bialgebras by Etingof and Kazhdan. Here we generalize this proof to color Lie bialgebras, which are Lie bialgebras graded by an arbitrary abelian group and symmetry given by a bicharacter. Before giving the details of the proof, we first recall the definitions and basic properties of color Lie algebras and bialgebras. Also a generalization of the Grand Crochet introduced by Lecomte and Roger to the color setting is given. Using the Grand Crochet, we also provide a cohomology for color Lie bialgebras. In the second part, we study different type of Hom-algebras, especially Hom-Lie and Hom-associative algebras. Hom-algebras are algebras were the defining relations, e.g. the associativity, are twisted by a linear map alpha called structure map. We first recall the relevant definitions. Then we define a new cohomology for Hom-associative and Hom-Lie algebras called alpha-type Hochschild and Chevalley-Eilenberg cohomology respectively. We also show how these cohomologies can be used to study formal deformations, in the sense of Gerstenhaber, of Hom-associative and Hom-Lie algebras. We allow the deformation of the multiplication and the structure map. We also consider alpha type cohomologies for Hom-bialgebras. Moreover, we explore the corresponding homotopy Lie algebra structure such that the Maurer-Cartan elements are Hom-algebras
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Butin, Frédéric. « Structures de Poisson sur les Algèbres de Polynômes, Cohomologie et Déformations ». Thesis, Lyon 1, 2009. http://www.theses.fr/2009LYO10192/document.
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La quantification par déformation et la correspondance de McKay forment les grands thèmes de l'étude qui porte sur des variétés algébriques singulières, des quotients d'algèbres de polynômes et des algèbres de polynômes invariants sous l'action d'un groupe fini. Nos principaux outils sont les cohomologies de Poisson et de Hochschild et la théorie des représentations. Certains calculs formels sont effectués avec Maple et GAP. Nous calculons les espaces d'homologie et de cohomologie de Hochschild des surfaces de Klein, en développant une généralisation du Théorème de HKR au cas de variétés non lisses et utilisons la division multivariée et les bases de Gröbner. La clôture de l'orbite nilpotente minimale d'une algèbre de Lie simple est une variété algébrique singulière sur laquelle nous construisons des star-produits invariants, grâce à la décomposition BGS de l'homologie et de la cohomologie de Hochschild, et à des résultats sur les invariants des groupes classiques. Nous explicitons les générateurs de l'idéal de Joseph associé à cette orbite et calculons les caractères infinitésimaux. Pour les algèbres de Lie simples B, C, D, nous établissons des résultats généraux sur l'espace d'homologie de Poisson en degré 0 de l'algèbre des invariants, qui vont dans le sens de la conjecture d'Alev et traitons les rangs 2 et 3. Nous calculons des séries de Poincaré à 2 variables pour des sous-groupes finis du groupe spécial linéaire en dimension 3, montrons que ce sont des fractions rationnelles, et associons aux sous-groupes une matrice de Cartan généralisée pour obtenir une correspondance de McKay algébrique en dimension 3. Toute l'étude a donné lieu à 4 articlesDeformation quantization and McKay correspondence form the main themes of the study which deals with singular algebraic varieties, quotients of polynomial algebras, and polynomial algebras invariant under the action of a finite group. Our main tools are Poisson and Hochschild cohomologies and representation theory. Certain calculations are made with Maple and GAP. We calculate Hochschild homology and cohomology spaces of Klein surfaces by developing a generalization of HKR theorem in the case of non-smooth varieties and use the multivariate division and the Groebner bases. The closure of the minimal nilpotent orbit of a simple Lie algebra is a singular algebraic variety : on this one we construct invariant star-products, with the help of the BGS decomposition of Hochschild homology and cohomology, and of results on the invariants of the classical groups. We give the generators of the Joseph ideal associated to this orbit and calculate the infinitesimal characters. For simple Lie algebras of type B, C, D, we establish general results on the Poisson homology space in degree 0 of the invariant algebra, which support Alev's conjecture, then we are interested in the ranks 2 and 3. We compute Poincaré series of 2 variables for the finite subgroups of the special linear group in dimension 3, show that they are rational fractions, and associate to the subgroups a generalized Cartan matrix in order to obtain a McKay correspondence in dimension 3. All the study comes from 4 papers
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Torres, Ivan Francisco Ruiz. « Efeito da deformação por cortante no cálculo de edifícios de andares múltiplos com núcleos estruturais ». Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-13122017-154253/.
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O principal objetivo deste trabalho é realizar a análise estrutural de edifícios de andares múltiplos que apresentam núcleos resistentes, considerando a deformação pelo esforço cortante nos mesmos, bem como nos pilares. Para atingir esse objetivo, será preciso que o comportamento à flexão dos elementos verticais de contraventamento passe a ser regido pela teoria de barras de Timoshenko e não mais pela de Euler-Bernoulli. Foram então desenvolvidos algoritmos que, utilizando o Método dos Elementos Finitos (MEF), permitem calcular os fatores de forma de quaisquer seções transversais abertas de paredes delgadas pertencentes a núcleos estruturais, bem como a distribuição da tensão de cisalhamento na seção transversa em função do esforço cortante atuante. As alterações acima descritas foram feitas em um programa de análise de edifícios denominado CEASO 01, de autoria de MATIAS JR (1997). Embora esse programa realize análise não-linear geométrica, a consideração da deformação por cortante só foi implementada na análise linear. Apresentam-se, ao final, exemplos numéricos que permitem avaliar a influência da deformação pelo esforço cortante sobre os deslocamentos e esforços de núcleos resistentes e pilares.The main aim of this work is to perform structural analysis of multistory buildings with resistant cores, taking into account shear deformation in those elements, as well as in columns. To achieve this objective, the flexural behaviour of vertical elements must be governed by Timoshenko beam theory, rather than the Euler-Bernoulli theory. Procedures using the finite element method (FEM) were developped, which enable to evaluate shear correction factors of generic thin-walled open sections and shear stress distribution as a function of the shear resultant. Changes described above were made in a structural analysis program named CEASO 01, whose author is MATIAS JR (1997). Even though this program is able to perform nonlinear analysis, only in linear analysis the effect of shear deformation is taken into account. Numerical examples are provided, which enable to evaluate the influence of taking into account shear deformation on displacements and stress resultants of resistant cores and columns.
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Brito, Ieverton Caiandre Andrade. « Influência da ciclagem térmica nas temperaturas de transformação de fase e quantificação das deformações residuais em ligas com memória de forma cu-al-be-nb-ni ». Universidade Federal da Paraíba, 2012. http://tede.biblioteca.ufpb.br:8080/handle/tede/5339.
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In this work was evaluated the influence of multiple quenching in the peak temperatures of phase transformation (PTPT) in the alloy Cu-11.8Al-0.6Be-0.5Nb-0.27Ni (%wt), as well as the influence that deformation applied in temperatures above Ms, at nominal composition Cu-11.8Al-0.6Be-0.5Nb-0.27Ni, Cu-11.8Al-0.55Be-0.5Nb-0.27Ni and Cu-11.8Al-4Nb-2.16Ni-0.5Be, would have on the residual deformation. The alloys were melted, homogenized during 12h by 850ºC and machined using wire electroerosion. Then, the samples were quenched in water at room temperature and subsequently analyzed by optical microscopy, scanning electron microscopy, using energy dispersive x-ray, differential scanning calorimetric analysis and x-ray diffractometry. For samples quenched successively, it was found a large change in PTPT after 22 quenching, there is no reverse transformation in this range. From the 34th quenching, the PTPT remained constant around 420ºC and severe changes in your micrographs were detected. Nevertheless, there was no change in Cu/Al able to change the PTPT. Alloys with containing nominal composition 0.4% and 0.2%Be indicated strong influence of the Be in the PTPT. When analyzed by x-ray diffractometry, the sample with 0.2Be indicated the presence of β' and γ' phases, when aged by 530ºC. For quantifying the residual deformations, the samples were subjected to static tensile and loading/unloading tests. When subjected large deformation and temperature near Ms, the results showed a great residual deformation, whereas small deformations with temperatures above Af showed not to be viable. The alloy Cu-11.8Al-4Nb-2.16Ni-0.5Be when tractioned, showed excessive weakness even after treatment of solubilization.
Neste trabalho avaliou-se a influência de têmperas múltiplas, nas temperaturas de pico da transformação de fase (TPTF) e na microestrutura da liga Cu-11,8Al-0,6Be-0,5Nb-0,27Ni (% em peso), bem como a influência que deformações aplicadas, em temperaturas a partir de Ms, às ligas de composição nominal Cu-11,8Al-0,6Be-0,5Nb-0,27Ni, Cu-11,8Al-0,55Be-0,5Nb-0,27Ni e Cu-11,8Al-4Nb-2,16Ni-0,5Be, teriam nas deformações residuais. As ligas foram fundidas, homogeneizadas durante 12h a 850ºC e usinadas via eletroerosão à fio. Em seguida, os corpos de prova foram temperados em água a temperatura ambiente sendo posteriormente analisadas via microscopia óptica, microscopia eletrônica de varredura, utilizando-se energia dispersiva de raios-x (EDS), análise calorimétrica diferencial de varredura (DSC) e difratometria de raios-X. Para as amostras cicladas termicamente, verificou-se que após 22 têmperas uma mudança significativa nas TPTF ocorre, não havendo a partir deste intervalo transformação reversa. A partir da 34ª têmpera, as TPTF permaneceram constantes em torno de 420ºC e as micrografias indicaram mudanças severas em suas microestruturas. Não obstante, não se verificou alteração na relação Cu/Al capaz de alterar as TPTF. As amostras contendo composição nominal de 0,4% e 0,2% de Be indicaram que as ligas estudadas são fortemente influenciadas pela presença do Be. Quando analisada por difratometria de raios-x, a amostra com 0,2Be indicou a presença das fases β e γ , quando submetida a tratamento de envelhecimento a 530ºC. Para a quantificação das deformações residuais, os corpos de prova foram submetidos aos ensaios de tração estática e de carregamento/descarregamento. As amostras submetidas a deformações próximas as de ruptura e com temperatura de ensaio próximo a Ms mostraram resultar em deformações residuais de maiores intensidades, enquanto quedeformações de pequena magnitude, com temperaturas acima de Af, mostraram não serem viáveis. A liga de composição nominal Cu-11,8Al-4Nb-2,16Ni-0,5Be, quando ensaiada sob tração, mostrou fragilidade excessiva mesmo após tratamento térmico de solubilização.
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Lefèvre, Louis-Clément. « Théorie de Hodge mixte et variétés des représentations des groupes fondamentaux des variétés algébriques complexes ». Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAM029/document.
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La théorie de Hodge mixte de Deligne fournit des structures supplémentaires sur les groupes de cohomologie des variétés algébriques complexes. Depuis, des structures de Hodge mixtes ont été construites sur les groupes d'homotopie rationnels de telles variétés par Morgan et Hain. Dans cette lignée, nous construisons des structures de Hodge mixtes sur des invariants associés aux représentations linéaires des groupes fondamentaux des variétés algébriques complexes lisses. Le point de départ est la théorie de Goldman et Millson qui relie la théorie des déformations de telles représentations à la théorie des déformations via les algèbres de Lie différentielles graduées. Ceci a été relu par P. Eyssidieux et C. Simpson dans le cas des variétés kählériennes compactes. Dans le cas non compact, et pour des représentations d'image finie, Kapovich et Millson ont construit seulement des graduations non canoniques. Pour construire des structures de Hodge mixtes dans le cas non compact et l'unifier avec le cas compact traité par Eyssidieux-Simpson, nous ré-écrivons la théorie de Goldman-Millson classique en utilisant des idées plus modernes de la théorie des déformations dérivée et une construction d'algèbres L-infini due à Fiorenza et Manetti. Notre structure de Hodge mixte provient alors directement du H^0 d'un complexe de Hodge mixte explicite, de façon similaire à la méthode de Hain pour le groupe fondamental, et dont la fonctorialité apparaît clairementThe mixed Hodge theory of Deligne provides additional structures on the cohomology groups of complex algebraic varieties. Since then, mixed Hodge structures have been constructed on the rational homotopy groups of such varieties by Morgan and Hain. In this vein, we construct mixed Hodge structures on invariants associated to linear representations of fundamental groups of smooth complex algebraic varieties. The starting point is the theory of Goldman and Millson that relates the deformation theory of such representations to the deformation theory via differential graded Lie algebras. This was reviewed by P. Eyssidieux and C. Simpson in the case of compact Kähler manifolds. In the non-compact case, and for representations with finite image, Kapovich and Millson constructed only non-canonical gradings. In order to construct mixed Hodge structures in the non-compact case and unify it with the compact case treated by Eyssidieux-Simpson, we re-write the classical Goldman-Millson theory using more modern ideas from derived deformation theory and a construction of L-infinity algebras due to Fiorenza and Manetti. Our mixed Hodge structure comes then directly from the H^0 of an explicit mixed Hodge complex, in a similar way as the method of Hain for the fundamental group, and whose functoriality appears clearly
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Mansouri, Lotfi zoher. « Analyse des instabilités plastiques dans les matériaux ductiles endommageables : application à la prédiction de la striction et de la formabilité des tôles métalliques ». Thesis, Paris, ENSAM, 2014. http://www.theses.fr/2014ENAM0059/document.
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La striction diffuse et localisée sont des phénomènes précurseurs à la rupture ductile et représentent l'une des principales causes de rebut des pièces métalliques au cours de leur mise en forme. La mise en œuvre d'outils théoriques et numériques capables de prédire l'apparition de ces défauts s'avère nécessaire pour des raisons économiques et environnementales. Ces outils nécessitent en partie l'intégration d'un modèle de comportement adéquat permettant de reproduire les phénomènes physiques mis en jeu. Un tel modèle de comportement est ensuite couplé à un indicateur d'instabilité plastique offrant la possibilité de prédire de manière fiable les phénomènes de striction diffuse et localisée. Dans ce travail de thèse, nous avons considéré certains modèles d'endommagement micromécaniques basés sur l'approche de Gurson, et qui ont été couplés à différents critères d'instabilités plastiques reposant sur l'Analyse de Bifurcation. L'implantation numérique des modèles retenus a été réalisée dans le code de calcul par éléments finis Abaqus/Standard. En ce qui concerne les modèles d'endommagement, plusieurs schémas d'intégrations ont été testés afin d'analyser leur performance et leur robustesse lorsque le comportement présente un effet adoucissant. L'approche combinant le modèle de comportement et les critères de striction a été utilisée pour prédire les limites de formabilité en striction diffuse et localisée de plusieurs matériaux métalliques. Les résultats obtenus ont permis de dresser une hiérarchisation théorique et numérique des critères de striction utilisésDiffuse and localized necking are precursors to ductile fracture, and represent one of the main causes of metal parts rejection during forming operations. The implementation of theoretical and computational tools to predict the occurrence of these defects turns out to be necessary for economic and environmental reasons. These tools require in part the introduction of an appropriate behavior model in order to reproduce the physical phenomena involved during forming operations. Such a behavior model is then coupled to a plastic instability indicator providing the ability to reliably predict diffuse and localized necking. In the present work, we considered a micromechanical damage models based on Gurson's approach, which were coupled to different plastic instabilities criteria, based on Bifurcation Analysis. The numerical implementation of these models was carried within the implicit finite element code Abaqus/Standard. With regard to the damage models, several integration schemes were tested to analyze their performance and robustness when the behavior exhibits softening effect. The approach combining the Gurson's damage model and necking criteria has been applied for the prediction of formability limits of several metallic materials. The obtained results allowed establishing a theoretical and numerical classification between the necking criteria used in this work
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Hapsari, Gemala. « Identification of inelastic cyclic behaviour of thin metal sheets under very large strain from instrumented micro forming process ». Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCD010.
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Le succès de l'industrialisation des micro-produits dépend des processus de conception et de fabrication. Une étape cruciale est la caractérisation du matériau utilisé dans les simulations numériques. Bien qu’il confère certaines propriétés mécaniques au matériau, l’essai de traction est loin de représenter la déformation complète subie par le matériau. Par conséquent, un autre test, Micro Incremental Deformation (Micro InDef), test présentant une déformation non homogène et riche en information, est développé sur la base du micro formage incrémental mono-point (µSPIF).Pour modéliser la formabilité du matériau (en particulier l'endommagement de matériaux), le modèle de Lemaitre est choisi en raison de sa capacité à modéliser le comportement du matériau en s'appuyant sur la mécanique des milieux continus et la thermodynamique de processus irréversibles. Dans cette étude, le Micro InDef test en tant que test de caractérisation de matériau est validé. De plus, en utilisant une méthode d’identifiabilité, il est prouvé que les paramètres matériaux identifiés sont des paramètres physiques, et non un simple lissage mathématique. Une fois le modèle de Lemaitre identifié, des tests expérimentaux et des simulations éléments finis sont effectués sur des tests de traction, des tests de cisaillement, des courbes limites de formage et des essais hors plan, afin de vérifier la fiabilité et l'adaptabilité de notre identification.Cette étude est finalement appliquée à un projet industriel dans le domaine des connecteurs, qui utilise principalement les alliages de cuivre comme matériau constitutifsThe success of micro product's industrialization depends on the conception, design and manufacturing process. A crucial step is the characterization of the material used in the numerical simulations. Although it gives some mechanical properties of material, tensile test is far from representing the complete deformation produced in the material. Therefore another test, Micro Incremental Deformation (Micro InDef), test which has non homogeneous deformation and which is rich in charactérization data is developped, based on Micro Single Point Incremental Forming (µSPIF).To modelise the limit of formability (especially the damage of materials), Lemaitre's constitutive model is chosen due to its possibility to define the material behaviour by using continuum mechanics and thermodynamics of irreversible processes. Within this study, Micro InDef as material characterization test is validated. Moreover, the material parameters identified are proven to be physical parameters, instead of only mathematical fitting, using an identifiability method. Once Lemaitre's model is identified, experimental tests and finite element simulations are performed on tensile tests, shearing tests, forming limit tests and out-of-plane tests, to verify the reliability and adaptability of our identification.This study is applied in an industrial project within the connector domain, which use copper alloys
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TORTORELLA, ALFONSO GIUSEPPE. « Deformations of coisotropic submanifolds in Jacobi manifolds ». Doctoral thesis, 2017. http://hdl.handle.net/2158/1077777.
Texte intégralRésumé :
In this thesis, we investigate deformation theory and moduli theory of coisotropic submanifolds in Jacobi manifolds. Originally introduced by Kirillov as local Lie algebras with one dimensional fibers, Jacobi manifolds encompass, unifying and generalizing, locally conformal symplectic manifolds, locally conformal Poisson manifolds, and non-necessarily coorientable contact manifolds.
We attach an L-infinity-algebra to any coisotropic submanifold in a Jacobi manifold. Our construction generalizes and unifies analogous constructions by Oh-Park (symplectic case), Cattaneo-Felder (Poisson case), and Le-Oh (locally conformal symplectic case). As a completely new case we also associate an L-infinity-algebra with any coisotropic submanifold in a contact manifold. The L-infinity-algebra of a coisotropic submanifold S controls the formal coisotropic deformation problem of S, even under Hamiltonian equivalence, and provides criteria both for the obstructedness and for the unobstructedness at the formal level. Additionally we prove that if a certain condition ("fiberwise entireness") is satisfied then the L-infinity-algebra controls the non-formal coisotropic deformation problem, even under Hamiltonian equivalence.
We associate a BFV-complex with any coisotropic submanifold in a Jacobi manifold. Our construction extends an analogous construction by Schatz in the Poisson setting, and in particular it also applies in the locally conformal symplectic/Poisson setting and the contact setting. Unlike the L-infinity-algebra, we prove that, with no need of any restrictive hypothesis, the BFV-complex of a coisotropic submanifold S controls the non-formal coisotropic deformation problem of S, even under both Hamiltonian equivalence and Jacobi equivalence.
Notwithstanding the differences there is a close relation between the approaches to the coisotropic deformation problem via L-infinity-algebra and via BFV-complex. Indeed both the L-infinity-algebra and the BFV-complex of a coisotropic submanifold S provide a cohomological reduction of S. Moreover they are L-infinity quasi-isomorphic and so they encode equally well the moduli space of formal coisotropic deformations of S under Hamiltonian equivalence.
In addition we exhibit two examples of coisotropic submanifolds in the contact setting whose coisotropic deformation problem is obstructed at the formal level. Further we provide a conceptual explanation of this phenomenon both in terms of the L-infinity-algebra and in terms of the BFV-complex.
Livres sur le sujet "Formal deformations"
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Conference Board of the Mathematical Sciences et NSF-CBMS Regional Conference in the Mathematical Sciences on Deformation Theory of Algebras and Modules (2011 : Raleigh, N.C.), dir. Deformation theory of algebras and their diagrams. Providence, Rhode Island : Published for the Conference Board of the Mathematical Sciences by the American Mathematical Society, 2012.
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author, Conrad Brian 1970, et Oort Frans 1935 author, dir. Complex multiplication and lifting problems. Providence, Rhode Island : American Mathematical Society, 2014.
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Rozenblyum, Nick, et Dennis Gaitsgory. Study in Derived Algebraic Geometry : Volume II : Deformations, Lie Theory and Formal Geometry. American Mathematical Society, 2020.
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Study in Derived Algebraic Geometry : Volume II : Deformations, Lie Theory and Formal Geometry. American Mathematical Society, 2017.
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Earl, Richard. Topology : A Very Short Introduction. Oxford University Press, 2019. http://dx.doi.org/10.1093/actrade/9780198832683.001.0001.
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Topology, the mathematical study of the properties that are preserved through the deformations, twistings, and stretchings of objects, is an important area of modern mathematics. Topology: A Very Short Introduction provides a sense of the more visual elements of topology (looking at surfaces) as well as covering the formal definition of continuity. Considering some of the eye-opening examples that led mathematicians to recognize a need for studying topology, it pays homage to the historical people, problems, and surprises that have propelled the growth of this field. As broad and fundamental as algebra and geometry, its study has important implications for science more generally, especially physics.
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Cambiar De Forma/changing Shape (Investigaciones / Investigations). Heinemann Library, 2004.
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Image Correlation for Shape Motion and Deformation Measurements. Springer, 2009.
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Schreier, Hubert, Michael A. Sutton et Jean-Jose Orteu. Image Correlation for Shape, Motion and Deformation Measurements : Basic Concepts,Theory and Applications. Springer London, Limited, 2009.
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Carmichael, Cathie. Nationalisms in International Conflict. Oxford University Press, 2017. http://dx.doi.org/10.1093/acrefore/9780190846626.013.268.
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Nationalism has made a significant contribution to state formation, but also to state deformation, secessionist movements, and wars. In international relations, nationalism has emerged as a particularly pressing problem over the question of disputed territorial boundaries. Indeed, nationalist movements seeking to change or revise boundaries by either negotiation, stealth, or force have been one of the most fundamental causes of both international and internal conflict in the modern era. The case of Bosnia-Hercegovina is a classic example of a long-running nationalist conflict which has had a profound empirical implications for both the social sciences and the humanities. The massacre at Srebrenica, ruled as genocide by the International Criminal Tribunal in The Hague, had a considerable impact beyond the Balkans and the Netherlands. While discussing genocide and crimes against humanity in fair historical context within parts of Serbia and enclaves within Republika Srpska and Montenegro today has remained a difficult and challenging task, a growing number of scholars have shown interest in comparative genocide and the way in which events can be meaningfully compared. The case of Bosnia has also provoked numerous debates in other areas, including the role of sexual crimes in war; obfuscation and genocide denial among extreme nationalists; issues of citizenship, reconstruction, and peacekeeping; the shortcomings of the international community (with particular reference to the United Nations); and the role of international law, especially the International Criminal Tribunal for the Former Yugoslavia (ICTY).
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Pediatric ICD-10-CM. American Academy of Pediatrics, 2015. http://dx.doi.org/10.1542/9781581109016.
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In this first edition, Pediatric ICD-10-CM: A Manual for Provider-Based Coding strives to bring to the pediatric provider, coder, and biller the most accurate and easy-to use manual on ICD-10-CM yet. Composed entirely with a pediatrics focus, this manual exclusively features codes and guidelines for physician- and provider-based coding, all in a simplified yet familiar format. The full draft of the ICD-10-CM code set comes in at well over 1,000 pages. This book condenses that large and potentially cumbersome book into 400 pages of the most relevant,pediatrics-related codes and guidelines. It also fully integrates into the tabular list specific chapter and code guidelines. Guideline are now included directly at the chapter and code level, ensuring that coders will always use the right codes in right circumstances Features include Integrated codes and guidelines Simplified yet familiar layout Tabular and indexed navigation Pediatric-focused and provider-based guidance And more... Contents Include: ICD-10-CM Official Guidelines for Coding and Reporting: FY 2015 Certain Infectious and Parasitic Diseases (A00-B99) Neoplasms (C00-D49) Diseases of the Blood and Blood-Forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) Endocrine, Nutritional and Metabolic Diseases (E00-E89) Mental, Behavioral and Neurodevelopmental Disorders (F01-F99) Diseases of the Nervous System (G00-G99) Diseases of the Eye and Adnexa (H00-H59) Diseases of the Ear and Mastoid Process (H60-H95) Diseases of the Circulatory System (I00-I99) Diseases of the Respiratory System (J00-J99) Diseases of the Digestive System (K00-K95) Diseases of the Skin and Subcutaneous Tissue (L00-L99) Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) Diseases of the Genitourinary System (N00-N99) Pregnancy, Childbirth, Certain Conditions Originating in the Perinatal Period (P00-P99) Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-Q99) Symptoms, Signs, and Abnormal Clinical and Laboratory Findings (R00-R99) Injury, Poisoning and Consequences of Certain Other External Causes (S00-T88) External Causes of Morbidity (V00-Y99) Factors Influencing Health Status and Contact With Health Services (Z00-Z99)
Chapitres de livres sur le sujet "Formal deformations"
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Stevens, Jan. « 6. Formal deformation theory ». Dans Deformations of Singularities, 45–53. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-36464-1_7.
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Fialowski, A. « An Example of Formal Deformations of Lie Algebras ». Dans Deformation Theory of Algebras and Structures and Applications, 375–401. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3057-5_5.
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Bäck, Per. « Multi-parameter Formal Deformations of Ternary Hom-Nambu-Lie Algebras ». Dans Springer Proceedings in Mathematics & ; Statistics, 455–60. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-7775-8_36.
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Katz, Gabriel. « Formal Deformations of Equivariant Genera, Fixed Point Formula and Universal Symmetry Blocks ». Dans Prospects in Topology (AM-138), sous la direction de Frank Quinn, 221–50. Princeton : Princeton University Press, 1996. http://dx.doi.org/10.1515/9781400882588-015.
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Hartshorne, Robin. « Formal Moduli ». Dans Deformation Theory, 99–148. New York, NY : Springer New York, 2009. http://dx.doi.org/10.1007/978-1-4419-1596-2_4.
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Wilde, M., et P. Lecomte. « Formal Deformations of the Poisson Lie Algebra of a Symplectic Manifold and Star-Products. Existence, Equivalence, Derivations ». Dans Deformation Theory of Algebras and Structures and Applications, 897–960. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3057-5_18.
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Almog, Joseph. « Is Natural Semantics Possible?—Ordinary English, Formal Deformations-cum-Reformations and the Limits of Model Theory ». Dans Jaakko Hintikka on Knowledge and Game-Theoretical Semantics, 49–108. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-62864-6_3.
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Green, Mark, et Phillip Griffiths. « Formal Deformation of Chow Groups ». Dans The Legacy of Niels Henrik Abel, 467–509. Berlin, Heidelberg : Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-642-18908-1_13.
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Böckle, Gebhard. « Deformations of Galois Representations ». Dans Elliptic Curves, Hilbert Modular Forms and Galois Deformations, 21–115. Basel : Springer Basel, 2013. http://dx.doi.org/10.1007/978-3-0348-0618-3_2.
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Conrad, Brian. « The Flat Deformation Functor ». Dans Modular Forms and Fermat’s Last Theorem, 373–420. New York, NY : Springer New York, 1997. http://dx.doi.org/10.1007/978-1-4612-1974-3_13.
Texte intégralActes de conférences sur le sujet "Formal deformations"
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Sloboda, Andrew R., et Bogdan I. Epureanu. « Optimally Designed Nonlinear Feedback Excitation for High-Sensitivity Sensing ». Dans ASME 2009 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2009. http://dx.doi.org/10.1115/smasis2009-1329.
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Employing sensitivity vector field (SVF) analysis in active micro-sensors can increase both their sensitivity and their ability to differentiate between changes in multiple sensor parameters. However, since SVF analysis is based on quantifying attractor deformations in state space, maximizing its effectiveness depends on selecting a sensor excitation that generates an attractor having suitable deformation with respect to the parameter(s) of interest. This paper addresses issues surrounding such system excitation design for a simple, linear vibration-based sensor having a combination of harmonic and nonlinear feedback excitation. In order to reframe the search for an optimal excitation as a search for a set of optimal control parameters, the excitation is considered to be of a specified form with a set of adjustable control parameters. Determining how to adjust the excitation parameters so as to maximize the magnitude of the resulting sensitivity vectors is then the formal goal. Using a pattern search method that avoids difficulties caused by bifurcations, we show that improved excitation can be designed reliably and efficiently. We also show that for short trajectory evolution times (suitable for “large” sensor perturbations) limit cycle behavior generates the best SVFs while for longer evolution times (suitable for “small” sensor perturbations) chaotic behavior may be more useful. Other issues discussed include the relative importance of various controller terms and the significance of harmonic excitation phase when generating sensitivity vectors.
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Rastgoftar, Hossein, Jean-Baptiste Jeannin et Ella Atkins. « Formal Specification of Continuum Deformation Coordination ». Dans 2019 American Control Conference (ACC). IEEE, 2019. http://dx.doi.org/10.23919/acc.2019.8814645.
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Bieliavsky, P., Piotr Kielanowski, S. Twareque Ali, Anatol Odzijewicz, Martin Schlichenmaier et Theodore Voronov. « Non-Formal Deformation Quantization and Symmetric Spaces ». Dans XXVIII WORKSHOP ON GEOMETRICAL METHODS IN PHYSICS. AIP, 2009. http://dx.doi.org/10.1063/1.3275595.
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Suciu, Ioana, Ioannis Kanellos et Thierry Moudenc. « Formal expressive indiscernibility underlying a prosodic deformation model ». Dans ExLing 2006 : 1st Tutorial and Research Workshop on Experimental Linguistics. ExLing Society, 2019. http://dx.doi.org/10.36505/exling-2006/01/0051/000051.
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Malinin, Len. « Design Under Contradictory Requirements ». Dans ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65108.
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This article presents a design method aimed at addressing contradictory requirements during the conceptual design activities or new product development. Of several methods aimed at developing a “good design” (not necessarily solving a contradiction), a general formal method was proposed in the Axiomatic Design Theory (ADT) by NP Suh [1]. ADT views design as a process that translates a set of functional requirements into a set of design parameters through a design matrix. The goal of the axiomatic design is to force a designer to start from scratch and explore the relationship between functions of the product and its design characteristics. Because the design characteristics in this approach are determined from scratch, the contradictions theoretically will be eliminated at a high level, before the design is developed in more detail. The ADT, however, does not offer specific tools to address contradictory requirements. Hegel’s Logic claims that “there is absolutely nothing whatever in which we cannot and must not point to contradictions“[2]. In this paper, we argue that with the right focus, contradictions can be leveraged to develop a stronger design solution. While contradictory requirements to product characteristics arise in almost every project, most often they are addressed by searching for a useful compromise in a highly iterative procedure. A more efficient approach, presented in this paper, satisfies both sides of a contradictory requirement (at different moments of time, or for different parts of the object, or at different sections of its non-linear characteristic). It is shown that in many cases, the most important step is reframing of the initial problem, which can be done by listing contradictory requirements and indicating to which parts of the object / moments of time/ stages of its life cycle they apply. Once it is done, the solution can often transpire from the reformulated problem statement, or can be generated using a very limited set of separation principles. An additional option, which has not been previously recommended for resolving contradictions, is separation of contradictory requirements in the space of material or object parameters, by selecting non-linear material or device characteristics. For instance, a medical device needs to meet different requirements in different tests: high elasticity (for the kink test) and at the same time high strength (for the burst test). This means that the target material should meet contradictory requirements to a single characteristic, its stress-deformation curve. The contradiction can be resolved using the fact that high elasticity (the kink test) is required at relatively low deformations whereas high strength (the burst test) is required at large deformations. Generally, for selection of a non-linear characteristic, it is proposed to use a morphological table with non-linear characteristics of a material or of similar devices based on different operation principles (such as different I-V curves of a current limiting device). Several case studies dealing with different subject matter applications illustrate the proposed method. The case studies include medical devices (peripherally inserted central catheter, vena cava filter), aerodynamic tractor-trailer devices, current limiting devices. The case studies are based on real life projects that resulted in patented designs.
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Ruiz-Armenteros, Antonio Miguel, Mario Sánchez-Gómez, José Manuel Delgado-Blasco, Matus Bakon, Ana Ruiz-Constán, Jesús Galindo-Zaldívar, Milan Lazecky, Miguel Marchamalo-Sacristán et Joaquim J. Sousa. « Monitoring instabilities by MT-InSAR in a mesa placed town (Arjona, Guadalquivir valley, South Spain) ». Dans 5th Joint International Symposium on Deformation Monitoring. Valencia : Editorial de la Universitat Politècnica de València, 2022. http://dx.doi.org/10.4995/jisdm2022.2022.13885.
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Cities in Spain use to be overgrown around old towns (preroman, roman and medieval) constructed on topographic defensive heights of singular geological features. In the upper Guadalquivir valley, a tabular body of Miocene sediments has been eroded forming mesas where most of its population has been living since middle age. As the towns grew, new neighborhoods settled towards the edges and cliffs of these mesas, in areas with high probabilities of instability. The town of Arjona is a good example of this geological-urbanistic setup, located on the tabular hill formed by clay marls topped by bioclastic limestones that protect it from erosion. Modern buildings from few sectors of the town show important cracks, even the 16th century bell-tower has a 4º inclination indicating problems in the foundations. Multi-temporal SAR interferometry (MT-InSAR) is a powerful technique to derive displacement time series over coherent targets on the Earth associated with geophysical or structural instabilities phenomena. In this work we use MT-InSAR with Sentinel-1 data to reveal that, at present day, the periphery of Arjona is active, being recognized a large landslide in the south side of this mesa town which affects buildings and civil infrastructures. In addition, field work is being carried out to investigate the sources of these instabilities.
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Sauthoff, Anni, Paul Köchert, Günther Prellinger, Tobias Meyer, Frank Pilarski, Stephanie Weinrich, Frank Schmaljohann et al. « Two multi-wavelength interferometers for large-scale surveying ». Dans 5th Joint International Symposium on Deformation Monitoring. Valencia : Editorial de la Universitat Politècnica de València, 2022. http://dx.doi.org/10.4995/jisdm2022.2022.13635.
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Deformation monitoring requires the detection of smallest changes, always at the limits of technical feasibility. Trying to push these limits further, we have realised two terrestrial ranging instruments: a long-range 1D electro-optic distance meter and a 3D multilateration-capable sensor system of 50 m range. The former one is intended as primary standard for the calibration of geodetic instrumentation with low uncertainty to the SI definition of the metre. The latter one is intended for monitoring larger monuments like VLBI antennas. In this contribution, we describe the technical challenges and our solutions for such instrumentation. We use the two-colour method for inline refractive index compensation. As common optical source, we developed a versatile multi-wavelength generator based on two Nd:YAG lasers stabilised by a phase-locked loop realised by Field Programmable Gate Arrays (FPGA). The 1D interferometer uses custom-designed achromatic optics and a mechanical frame optimised for form stability under field conditions. The phase demodulation system allows for maximum range flexibility from several meters up to several kilometres. The base ranging unit of the 3D multilateration system adheres to a different demodulation technique, which allows a relatively simple interferometer head design. This approach requires a sophisticated source modulation scheme limiting the applicability to distances over 15 m up to approximately 50 m in our case.
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Matveev, Konstantin I. « Computational Modeling of Planing Hull Dynamics and Slamming in Head Waves ». Dans ASME 2021 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/fedsm2021-65548.
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Abstract Fast boats often operate in planing regimes when they skim on the water surface and their weight is supported primarily by hydrodynamic forces. In the presence of waves, such hulls may experience large nonlinear motions and hydrodynamic loads, which limit their operational capabilities. To predict hull motions and loads and to optimize the hull shape and structure, one can take advantage of computational fluid dynamics tools that simulate these complex nonlinear flow processes and provide detailed hydrodynamic data, including pressure distribution on the hull and water spray. However, validation of these modeling approaches is needed in order to confidently use numerical tools for the boat design. In this study, numerical modeling is accomplished for dynamics of a realistic hull previously tested in controlled wave environments in towing tanks. Time-domain simulations were first carried out in regular head waves. Mesh-verification studies suggested appropriate numerical grid resolution. The hull’s heave motions, drag forces and bow accelerations were captured and compared with experimental data. The formal validation procedure was applied to confirm suitability of the current numerical approach. In the investigated regular-wave conditions, very pronounced slamming phenomenon was observed, when the hull re-entered water and experienced peak hydrodynamic loads. Pressure distributions on the hull surface and water surface deformations are presented for several time instances around the slamming event. In addition, numerical simulations were also conducted for random waves with statistical sea-wave parameters resembling those of the studied regular waves. The statistical boat responses, such as bow accelerations, heaving motions and drag forces, are compared to the corresponding metrics obtained in regular waves.
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Bru, Guadalupe, Juan J. Portela, Pablo Ezquerro, M. Inés Navarro, Alejandra Staller, Marta Béjar-Pizarro, Carolina Guardiola-Albert et al. « Imaging land subsidence in the Guadalentín River Basin (SE Spain) using Advanced Differential SAR Interferometry ». Dans 5th Joint International Symposium on Deformation Monitoring. Valencia : Editorial de la Universitat Politècnica de València, 2022. http://dx.doi.org/10.4995/jisdm2022.2022.13826.
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Aquifer overexploitation can lead to the irreversible loss of groundwater storage caused by the compaction or consolidation of unconsolidated fine-grained sediments resulting in land subsidence. Advanced Differential SAR Interferometry (A-DINSAR) is particularly efficient to monitor progressive ground movements, making it an appropriate method to study depleting aquifers undergoing overexploitation and land subsidence. The Guadalentín River Basin (Murcia, Spain) is a widely recognized subsiding area that exhibits the highest rates of groundwater-related land subsidence recorded in Europe (>10 cm/yr). The basin covers an extension of more than 500 km2 and is underlain by an overexploited aquifer-system formed by two contiguous hydraulically connected units (Alto Guadalentín and Bajo Guadalentín). Although during the last years the piezometric levels have partially stabilized, the ongoing aquifer-system deformation is evident and significant, as revealed by the A-DInSAR analysis presented. In this work, we submit the first vertical and horizontal (E-W) decomposition results of the LOS velocity and displacement time series of the whole Guadalentín Basin obtained from two datasets of Sentinel-1 SAR acquisitions in ascending and descending modes. The images cover the period from 2015 to 2021 and they were processed using the Parallel Small BAseline Subset (P-SBAS) implemented by CNR-IREA in the Geohazards Exploitation Platform (GEP) on-demand web tool, which is funded by the European Space Agency. The output ascending and descending measurement points of P-SBAS lie on the same regular grid, which is particularly suited for the geometrical decomposition. Time series displacements are compared to a permanent GNSS station located in the Bajo Guadalentín basin.
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Suzuki, Nobuhisa, Takekazu Arakawa et Andrei Arabey. « Pipeline Integrity in Seismic and Extremely Cold Regions ». Dans 2016 11th International Pipeline Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/ipc2016-64301.
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This paper discusses seismic integrity of a gas pipeline in extremely cold regions which pipeline consists of X70-grade high-strain line pipes with outside diameter of 1420 mm. Longitudinal compressive strain limits and max longitudinal compressive strain induced by compressive or bending deformation are discussed. The strain capacity in bending of the high strain line pipes tends to be high by 0.5% compared to the largest value within those calculated by some semi-empirical formulae proposed by former researchers. The pipeline may be subjected to axial and/or bending deformation due to ground deformations in discontinuous permafrost zones or stone run areas before an earthquake occurs there. Hence the effects of ground motion and ground deformations should be taken into account simultaneously to investigate the seismic integrity of a pipeline. In order to simply distinguish displacement controlled condition from load controlled condition, parameters including pipe-soil interaction properties are proposed. Design formulae were derived to calculate strain demand of a pipeline to endure the ground deformations, which parameters shall be applied to the deformation in the displacement controlled condition. Finally it was concluded that the high-strain pipes are effective to ensure pipeline integrity in extremely cold and seismically active regions.
Rapports d'organisations sur le sujet "Formal deformations"
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Todd, James T. Visual Perception of 3-Dimensional Form from Different Types of Optical Deformations. Fort Belvoir, VA : Defense Technical Information Center, novembre 1996. http://dx.doi.org/10.21236/ada326225.
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Nema, Arpit, et Jose Restrep. Low Seismic Damage Columns for Accelerated Bridge Construction. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, décembre 2020. http://dx.doi.org/10.55461/zisp3722.
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This report describes the design, construction, and shaking table response and computation simulation of a Low Seismic-Damage Bridge Bent built using Accelerated Bridge Construction methods. The proposed bent combines precast post-tensioned columns with precast foundation and bent cap to simplify off- and on-site construction burdens and minimize earthquake-induced damage and associated repair costs. Each column consists of reinforced concrete cast inside a cylindrical steel shell, which acts as the formwork, and the confining and shear reinforcement. The column steel shell is engineered to facilitate the formation of a rocking interface for concentrating the deformation demands in the columns, thereby reducing earthquake-induced damage. The precast foundation and bent cap have corrugated-metal-duct lined sockets, where the columns will be placed and grouted on-site to form the column–beam joints. Large inelastic deformation demands in the structure are concentrated at the column–beam interfaces, which are designed to accommodate these demands with minimal structural damage. Longitudinal post-tensioned high-strength steel threaded bars, designed to respond elastically, ensure re-centering behavior. Internal mild steel reinforcing bars, debonded from the concrete at the interfaces, provide energy dissipation and impact mitigation.
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Turner, E. C. Mesoproterozoic Borden Basin, northern Baffin Island. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/321825.
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The unmetamorphosed and nearly undeformed late Mesoproterozoic Borden Basin on northern Baffin Island exhibits sag, rift, and foreland-basin-like phases. A thin, partly subaqueous basal basalt is overlain by mature shallow-marine quartz arenite, upward-deepening siltstone and shale (marking the beginning of rifting), a complex suite of rift-delineated carbonate units containing two dramatic internal unconformities, and a flysch-molasse-like succession containing evidence of sediment derivation from the Grenville Orogen. Geochronological data indicate that deposition of most of the succession took place ca. 1100 to 1050 Ma. One of the carbonate intervals, Nanisivik Formation, is the main host of regional Zn-Pb showings including the past-producing Nanisivik orebody, which formed in the late Mesoproterozoic from low-temperature fluids, and which was emplaced under strong structural and stratigraphic controls. Minimal postdepositional deformation is limited to the emplacement of mafic dykes ca. 720 Ma and repeated reactivation of basement-rooted normal faults.
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Ryan, J. J., A. Zagorevski, N. R. Cleven, A J Parsons et N. L. Joyce. Architecture of pericratonic Yukon-Tanana terrane in the northern Cordillera. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/326062.
Texte intégralRésumé :
West-central Yukon and eastern Alaska are characterized by widespread metamorphic rocks that form part of the allochthonous, composite Yukon-Tanana terrane and parautochthonous North American margin. Structural windows through the Yukon-Tanana terrane expose parautochthonous North American margin in that broad region, particularly as mid-Cretaceous extensional core complexes. Both the Yukon-Tanana terrane and parautochthonous North American margin share the same Late Devonian history, making their discrimination difficult; however, distinct post-Late Devonian magmatic and metamorphic histories assist in discriminating Yukon-Tanana terrane from parautochthonous North American margin rocks. The suture between Yukon-Tanana terrane and parautochthonous North American margin is obscured by many episodes of high-strain deformation. Their main bounding structure is probably a Jurassic to Cretaceous thrust, which has been locally reactivated as a mid-Cretaceous extensional shear zone. Crustal-scale structures within composite Yukon-Tanana terrane (e.g. the Yukon River shear zone) are commonly marked by discontinuous mafic-ultramafic complexes. Some of these complexes represent orogenic peridotites that were structurally exhumed into the Yukon-Tanana terrane in the Middle Permian.
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Boily-Auclair, É., P. Mercier-Langevin, P. S. Ross et D. Pitre. Alteration and ore assemblages of the LaRonde Zone 5 (LZ5) deposit and Ellison mineralized zones, Doyon-Bousquet-LaRonde mining camp, Abitibi, Quebec. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329637.
Texte intégralRésumé :
The LaRonde Zone 5 (LZ5) mine is part of the Doyon-Bousquet-LaRonde mining camp and is located in the southern part of the Abitibi greenstone belt in northwestern Quebec. The LZ5 deposit consists of three stacked mineralized corridors: Zone 4, Zone 4.1, and Zone 5. Zones 4 and 4.1 are discontinuous satellite mineralized corridors, whereas Zone 5 represents the main mineralized body. The mineralized zones of the LZ5 deposit and adjacent Ellison property (Ellison A and B zones) are hosted in the strongly-deformed, 2699-2695 Ma transitional to calcalkaline, intermediate to felsic, volcanic and volcaniclastic rocks of the Bousquet Formation upper member, which is part of the Blake River Group (2704-2695 Ma). Zones 4, 4.1, and 5 at the LZ5 mine are hosted in intermediate volcanic and volcaniclastic rocks of the Westwood andesitic to rhyodacitic unit (unit 5.1a), which forms the base of the upper member of the Bousquet Formation. The Ellison Zone A is hosted higher up in the stratigraphic sequence within a newly described intermediate volcanic unit. The Ellison Zone B is hosted in felsic volcanic and volcaniclastic rocks of the Westwood feldsparphyric rhyolite dome (subunit 5.3a-(b)). Mineralization in all three zones of the LZ5 deposit consists of discordant networks of millimeter- to centimeter-thick pyrite ±chalcopyrite ±sphalerite ±pyrrhotite veins and veinlets (10-20 % of the volume of the rock) and, to a lesser extent, very finely disseminated pyrite and boudinaged veins (less than or equal to 5 vol. % each) in strongly altered host rocks. Gold commonly occurs as microscopic inclusions in granoblastic pyrite and at the triple junction between recrystallized grains. The veins, stockworks, and disseminations were intensely folded and transposed in the steeply south-dipping, east-west trending S2 foliation. The vein network is at least partly discordant to the stratigraphy. A distal alteration halo envelops the LZ5 mineralized corridors and consists of a sericite-carbonate-chlorite- feldspar ±biotite assemblage. A proximal sericite-carbonate-chlorite-pyrite-quartz- feldspar-biotite ±epidote alteration assemblage is present within the LZ5 mineralized zones. A local proximal alteration assemblage of sericite-quartz-pyrite is also locally developed within Zone 4 and Zone 5 of the LZ5 deposit. Mass gains in Fe2O3 (t) and K2O, and mass losses in CaO, MgO, Na2O, and locally SiO2, are characteristic of the LZ5 alteration zones. The Ellison zone A and B are similar to LZ5 in terms of style of mineralization, but thin (10-20 cm) veins or bands of semi-massive to massive, finely recrystallized disseminated pyrite (0.1-1 mm) are distinctive. Chalcopyrite and sphalerite are also slightly more abundant in the mineralized corridors of the Ellison property and are usually associated with elevated gold grades. The zones are also slightly richer than at LZ5 in terms of gold and silver content, but narrower and less continuous in general. The Ellison Zone A is characterized by gains in Fe2O3 (t) and K2O and losses in CaO, MgO, Na2O, and SiO2. Gains in Fe2O3 (t) and local gains in K2O, MgO, and MnO, and losses in CO2, Na2O, P2O5, and SiO2, characterize the felsic host rocks of the Zone B corridor. The style of mineralization at LZ5 (pyrite ±chalcopyrite veins and veinlets, ±disseminated pyrite with low base metal content), its setting (i.e. in rocks of intermediate composition at the base of the upper member of the Bousquet Formation), and the geometry of its ore zones (stacked lenses of sulfide veins and veinlets, without massive sulfide lenses) differ from the other major deposits of the Doyon-Bousquet-LaRonde mining camp. Despite these differences, this study indicates that the LZ5 and Ellison mineralized corridors are of synvolcanic hydrothermal origin and have most likely been formed by convective circulation of seawater below the seafloor. An influx of magmatic fluids from the Mooshla synvolcanic intrusive complex or its parent magma chamber could explain the Au enrichment at LZ5, as has been suggested for other deposits of the camp. Evidence for a pre-deformation synvolcanic mineralization at LZ5 includes ductile deformation and recrystallization of the sulfides, the stacked nature of its ore zones, subconcordant alteration halos that envelop the mineralized corridors, evidence that the mineralized system was already active when the LZ5 lenses were deposited and control on mineralization by primary volcanic features such as the permeability and porosity of the volcanic rocks.
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Harris, L. B., P. Adiban et E. Gloaguen. The role of enigmatic deep crustal and upper mantle structures on Au and magmatic Ni-Cu-PGE-Cr mineralization in the Superior Province. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328984.
Texte intégralRésumé :
Aeromagnetic and ground gravity data for the Canadian Superior Province, filtered to extract long wavelength components and converted to pseudo-gravity, highlight deep, N-S trending regional-scale, rectilinear faults and margins to discrete, competent mafic or felsic granulite blocks (i.e. at high angles to most regional mapped structures and sub-province boundaries) with little to no surface expression that are spatially associated with lode ('orogenic') Au and Ni-Cu-PGE-Cr occurrences. Statistical and machine learning analysis of the Red Lake-Stormy Lake region in the W Superior Province confirms visual inspection for a greater correlation between Au deposits and these deep N-S structures than with mapped surface to upper crustal, generally E-W trending, faults and shear zones. Porphyry Au, Ni, Mo and U-Th showings are also located above these deep transverse faults. Several well defined concentric circular to elliptical structures identified in the Oxford Stull and Island Lake domains along the S boundary of the N Superior proto-craton, intersected by N- to NNW striking extensional fractures and/or faults that transect the W Superior Province, again with little to no direct surface or upper crustal expression, are spatially associated with magmatic Ni-Cu-PGE-Cr and related mineralization and Au occurrences. The McFaulds Lake greenstone belt, aka. 'Ring of Fire', constitutes only a small, crescent-shaped belt within one of these concentric features above which 2736-2733 Ma mafic-ultramafic intrusions bodies were intruded. The Big Trout Lake igneous complex that hosts Cr-Pt-Pd-Rh mineralization west of the Ring of Fire lies within a smaller concentrically ringed feature at depth and, near the Ontario-Manitoba border, the Lingman Lake Au deposit, numerous Au occurrences and minor Ni showings, are similarly located on concentric structures. Preliminary magnetotelluric (MT) interpretations suggest that these concentric structures appear to also have an expression in the subcontinental lithospheric mantle (SCLM) and that lithospheric mantle resistivity features trend N-S as well as E-W. With diameters between ca. 90 km to 185 km, elliptical structures are similar in size and internal geometry to coronae on Venus which geomorphological, radar, and gravity interpretations suggest formed above mantle upwellings. Emplacement of mafic-ultramafic bodies hosting Ni-Cr-PGE mineralization along these ringlike structures at their intersection with coeval deep transverse, ca. N-S faults (viz. phi structures), along with their location along the margin to the N Superior proto-craton, are consistent with secondary mantle upwellings portrayed in numerical models of a mantle plume beneath a craton with a deep lithospheric keel within a regional N-S compressional regime. Early, regional ca. N-S faults in the W Superior were reactivated as dilatational antithetic (secondary Riedel/R') sinistral shears during dextral transpression and as extensional fractures and/or normal faults during N-S shortening. The Kapuskasing structural zone or uplift likely represents Proterozoic reactivation of a similar deep transverse structure. Preservation of discrete faults in the deep crust beneath zones of distributed Neoarchean dextral transcurrent to transpressional shear zones in the present-day upper crust suggests a 'millefeuille' lithospheric strength profile, with competent SCLM, mid- to deep, and upper crustal layers. Mechanically strong deep crustal felsic and mafic granulite layers are attributed to dehydration and melt extraction. Intra-crustal decoupling along a ductile décollement in the W Superior led to the preservation of early-formed deep structures that acted as conduits for magma transport into the overlying crust and focussed hydrothermal fluid flow during regional deformation. Increase in the thickness of semi-brittle layers in the lower crust during regional metamorphism would result in an increase in fracturing and faulting in the lower crust, facilitating hydrothermal and carbonic fluid flow in pathways linking SCLM to the upper crust, a factor explaining the late timing for most orogenic Au. Results provide an important new dataset for regional prospectively mapping, especially with machine learning, and exploration targeting for Au and Ni-Cr-Cu-PGE mineralization. Results also furnish evidence for parautochthonous development of the S Superior Province during plume-related rifting and cannot be explained by conventional subduction and arc-accretion models.
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Lacerda Silva, P., G. R. Chalmers, A. M. M. Bustin et R. M. Bustin. Gas geochemistry and the origins of H2S in the Montney Formation. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329794.
Texte intégralRésumé :
The geology of the Montney Formation and the geochemistry of its produced fluids, including nonhydrocarbon gases such as hydrogen sulfide were investigated for both Alberta and BC play areas. Key parameters for understanding a complex petroleum system like the Montney play include changes in thickness, depth of burial, mass balance calculations, timing and magnitudes of paleotemperature exposure, as well as kerogen concentration and types to determine the distribution of hydrocarbon composition, H2S concentrations and CO2 concentrations. Results show that there is first-, second- and third- order variations in the maturation patterns that impact the hydrocarbon composition. Isomer ratio calculations for butane and propane, in combination with excess methane estimation from produced fluids, are powerful tools to highlight effects of migration in the hydrocarbon distribution. The present-day distribution of hydrocarbons is a result of fluid mixing between hydrocarbons generated in-situ with shorter-chained hydrocarbons (i.e., methane) migrated from deeper, more mature areas proximal to the deformation front, along structural elements like the Fort St. John Graben, as well as through areas of lithology with higher permeability. The BC Montney play appears to have hydrocarbon composition that reflects a larger contribution from in-situ generation, while the Montney play in Alberta has a higher proportion of its hydrocarbon volumes from migrated hydrocarbons. Hydrogen sulphide is observed to be laterally discontinuous and found in discrete zones or pockets. The locations of higher concentrations of hydrogen sulphide do not align with the sulphate-rich facies of the Charlie Lake Formation but can be seen to underlie areas of higher sulphate ion concentrations in the formation water. There is some alignment between CO2 and H2S, particularly south of Dawson Creek; however, the cross-plot of CO2 and H2S illustrates some deviation away from any correlation and there must be other processes at play (i.e., decomposition of kerogen or carbonate dissolution). The sources of sulphur in the produced H2S were investigated through isotopic analyses coupled with scanning electron microscopy, energy dispersive spectroscopy, and mineralogy by X-ray diffraction. The Montney Formation in BC can contain small discrete amounts of sulphur in the form of anhydrite as shown by XRD and SEM-EDX results. Sulphur isotopic analyses indicate that the most likely source of sulphur is from Triassic rocks, in particular, the Charlie Lake Formation, due to its close proximity, its high concentration of anhydrite (18-42%), and the evidence that dissolved sulphate ions migrated within the groundwater in fractures and transported anhydrite into the Halfway Formation and into the Montney Formation. The isotopic signature shows the sulphur isotopic ratio of the anhydrite in the Montney Formation is in the same range as the sulphur within the H2S gas and is a lighter ratio than what is found in Devonian anhydrite and H2S gas. This integrated study contributes to a better understanding of the hydrocarbon system for enhancing the efficiency of and optimizing the planning of drilling and production operations. Operators in BC should include mapping of the Charlie Lake evaporites and structural elements, three-dimensional seismic and sulphate ion concentrations in the connate water, when planning wells, in order to reduce the risk of encountering unexpected souring.
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TEST ON RESILIENCE CAPACITY OF SELF-CENTERING BUCKLING RESTRAINED BRACE WITH DISC SPRINGS. The Hong Kong Institute of Steel Construction, août 2022. http://dx.doi.org/10.18057/icass2020.p.156.
Texte intégralRésumé :
The properly constructed buckling restrained braces (BRBs) usually have good ductility and energy dissipation capacity and therefore can be used in braced steel frames. However, large residual plastic deformation of the BRBs deteriorates their resilience capacity and hence results in large residual deformation of the buckling restrained braced steel frames (BRBFs) under large drifts. To reduce the residual deformation of BRB while keeping good ductility and energy dissipation capacity, a new self-centering buckling restrained brace (SCBRB), letting both BRB part and self-centering part work in parallel, is proposed. The self-centering capacity of SCBRB is provided by a combination of pre-compressed disc springs, which provides restoring forces and facilitates reduction of the residual deformation of the BRB. The BRB is composed of a core steel plate brace, a restraining member formed by the circular steel tube filled with mortar, and debonding materials between them. By quasi-static tests, one self-centering buckling restrained brace specimen (SCBRB) and one pure BRB specimen were tested to mainly examine the constructional details and hysteretic behavior of SCBRB. The material and configuration details of core steel plate brace in both the SCBRB and the pure BRB are the same for comparison. The test results show that, compared with the pure BRB which still exhibits large residual deformation, the SCBRB presents a flag-shape hysteretic performance and its residual deformation decreases significantly. The hysteretic curves of both the SCBRB and the pure BRB are stable before tension fracture of plate brace due to low cyclic fatigue, and the other components remained intact.
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BOND-SLIP TESTING AND PERFORMANCE EVALUATION OF SEMI-RIGID FLANGE FOLDED WEB SHEAR KEYS. The Hong Kong Institute of Steel Construction, décembre 2022. http://dx.doi.org/10.18057/ijasc.2022.18.4.3.
Texte intégralRésumé :
The shear key is crucial to the overall mechanical performance of the structure. A new type of semi-rigid connector-flange folded web shear key was proposed to determine the effective unity of higher bearing capacity and deformation. A total of five groups of specimens were designed, and the push-out test method was used to evaluate the ultimate bearing capacity, bond-slip process, failure mode, and strain distribution of the new shear key. The results show that before sliding, the embedded effect of the concrete and shear key is significant, and it has a significant sliding stiffness. After sliding, the steel plate in the middle of the opening of the outer folded plate buckles, which shows certain semi-rigid characteristics. Compared with equal-area studs, the bearing capacity of the new shear key is increased by more than 40%, and the deformation capacity exceeds 60 %, indicating good bond-slip performance. The constraint range of the shear key is greatly improved compared with the stud, and a trapezoidal area of constraint centered on the shear key is formed, accounting for more than half of the area of the concrete slab. Based on an experimental study, a practical calculation method of ultimate bearing capacity of the shear key is proposed, which can meet engineering safety requirements. Based on the analysis of bond-slip characteristics of different forms of shear keys, compared with the rigid T-shaped shear key, the slip load and ultimate bearing capacity of the new shear key are found to be increased by 39 % and 74 %, respectively, and the deformation capacity is increased more than 10-fold. Compared with the flexible stud shear connectors, the sliding load is increased by 86 %, the ultimate bearing capacity is increased more two-fold, and the stiffness is increased by nearly five times. The device exhibits good comprehensive performance.
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STRESS RESPONSE AND INITIAL STIFFNESS OF SIDE PLATE CONNECTIONS TO WCFT COLUMNS. The Hong Kong Institute of Steel Construction, septembre 2021. http://dx.doi.org/10.18057/ijasc.2021.17.3.9.
Texte intégralRésumé :
To study the mechanism of load transfer in double-side-plate connections between I-beams and wall-type concrete-filled steel tubular columns, a pseudo-static experiment and finite element analysis were conducted for two full-scaled specimens. The results revealed that the primary load was transmitted along an S-shaped path in the side plate, and the primary strain occurred in an X-shaped region between the left and right steel beam flanges. The shear force in the steel beam web was transmitted first to the side plate centre and then to the joint area, where the side plate, steel tube web, and concrete all resisted the internal force. Based on principal component methods, a calculation formula was established for initial rotational stiffness that comprehensively considers the influence of the tensions, compression, and shear deformation of the cover plate, side plate, and web. Comparing this formula with an existing model showed that the proposed formula is suitable for new types of side plate joints. Moreover, it can accurately calculate the initial rotational stiffness of the joint, thus providing a reliable basis for future engineering design.