subject:(Shear locking)

1. Arthur Álax de Araújo Albuquerque. Implementação de elementos finitos de barra e placa para a análise de esforços em tabuleiros de pontes por meio de superfícies de influência.

Degree: 2014, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/18/18134/tde-28072014-093844/

►

Este trabalho consiste em analisar os esforços em tabuleiros de pontes por meio de superfícies de influência. Para isto, o método dos elementos finitos (MEF)… (more)

▼

Este trabalho consiste em analisar os esforços em tabuleiros de pontes por meio de superfícies de influência. Para isto, o método dos elementos finitos (MEF) é utilizado e os resultados são comparados com os das tabelas de Rüsch. Os elementos finitos de barra, representando longarinas e transversinas, e placa, as lajes do tabuleiro, são implementados no código SIPlacas. Estes elementos finitos são formulados pelas teorias de viga Timoshenko e placa Reissner-Mindlin, respectivamente. Estes apresentam problema de travamento de força cortante (Shear Locking), que é contornado por duas propostas: o artifício matemático da integração reduzida e elementos finitos com campo assumido de deformação de força cortante (CADFC). Verifica-se que os elementos com aproximações quadráticas para os deslocamentos e com CADFC são os que melhor se adequam à proposta de análise da presente pesquisa. Tais elementos apresentam convergência de resultados considerando estruturas com baixa discretização. Os resultados analisados foram o deslocamento, momento fletor e força cortante. Posteriormente realiza-se um estudo de caso de uma ponte em viga. O tabuleiro da ponte é calculado utilizando-se as tabelas de Rüsch e o código SIPlacas. O cálculo dos esforços pelo SIPlacas é realizado de três maneiras. Na primeira consideram-se os painéis de lajes do tabuleiro isolados; na segunda o tabuleiro está sobre apoios não deslocáveis; e na terceira, o tabuleiro apresenta-se com vigas acopladas. Foi concluído que a terceira configuração, cuja representação melhor se aproxima da estrutura real de análise, apresentou os menores esforços internos.

This work aims at the analysis of bridge deck stresses through influence surfaces. The finite element method (FEM) is used and the results are compared with those of Rüsch\'s tables. The bar and plate finite elements represent stringers, cross beams and slabs bridge deck. These finite elements are implemented in the SIPlacas code and the theories of Timoshenko beam and Reissner-Mindlin plate are used to theirs formulation. The Shear Locking problem is solved by two proposals: reduced integration and definition of element with transversal shear strain assumed (TSSA). The elements with quadratic approximations for the displacements and TSSA are the best suited to the proposed analysis of this research. Such elements have convergence of results considering structures with low discretization. Displacement, bending moment and shear force were the results analyzed. Subsequently a case study on a beam bridge was carried out. The bridge deck is calculated using Rüsch\'s tables and SIPlacas code. The calculation of the internal forces by SIPlacas is performed in three ways. The first one considers the slabs isolated panels; the second, the slab deck is on a rigid support; and third, the slab deck is on deformable supports. It was concluded that the third configuration showed the lowest internal forces. This configuration is the optimum representation to the structure analysis.

Advisors/Committee Members: Vladimir Guilherme Haach, Valério da Silva Almeida, Roberto Chust Carvalho.

Subjects/Keywords: Elementos finitos; Pontes; Reissner-Mindlin; Shear locking; Superfície de influência; Tabelas de Rüsch; Timoshenko; Bridges; Finite elements; Influence surface; Reissner-Mindlin; Rüsch's tables; Shear locking; Timoshenko

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Albuquerque, A. �. d. A. (2014). Implementação de elementos finitos de barra e placa para a análise de esforços em tabuleiros de pontes por meio de superfícies de influência. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/18/18134/tde-28072014-093844/

Chicago Manual of Style (16^th Edition):

Albuquerque, Arthur Álax de Araújo. “Implementação de elementos finitos de barra e placa para a análise de esforços em tabuleiros de pontes por meio de superfícies de influência.” 2014. Masters Thesis, University of São Paulo. Accessed April 16, 2021. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-28072014-093844/.

MLA Handbook (7^th Edition):

Albuquerque, Arthur Álax de Araújo. “Implementação de elementos finitos de barra e placa para a análise de esforços em tabuleiros de pontes por meio de superfícies de influência.” 2014. Web. 16 Apr 2021.

Vancouver:

Albuquerque A�dA. Implementação de elementos finitos de barra e placa para a análise de esforços em tabuleiros de pontes por meio de superfícies de influência. [Internet] [Masters thesis]. University of São Paulo; 2014. [cited 2021 Apr 16]. Available from: http://www.teses.usp.br/teses/disponiveis/18/18134/tde-28072014-093844/.

Council of Science Editors:

Albuquerque A�dA. Implementação de elementos finitos de barra e placa para a análise de esforços em tabuleiros de pontes por meio de superfícies de influência. [Masters Thesis]. University of São Paulo; 2014. Available from: http://www.teses.usp.br/teses/disponiveis/18/18134/tde-28072014-093844/

University of Florida

2. Chen, Hailong. Mixed Formulation Using Implicit Boundary Finite Element Method.

Degree: MS, Mechanical Engineering - Mechanical and Aerospace Engineering, 2012, University of Florida

URL: https://ufdc.ufl.edu/UFE0044151

► Implicit Boundary Finite Element Method (IBFEM) is a mesh independent finite element method, which is motivated by the desire to avoid mesh generation difficulties in… (more)

Subjects/Keywords: Bending moments; Cantilever plates; Convergent boundaries; Finite element method; Geometry; Mindlin plates; Mindlin Reissner plate theory; Plate theory; Shape functions; Structural deflection; 2d-shell – boundary – formulation – implicit – mesh-independent – mindlin – mixed – plate – shear-locking – volummetric-locking

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chen, H. (2012). Mixed Formulation Using Implicit Boundary Finite Element Method. (Masters Thesis). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0044151

Chicago Manual of Style (16^th Edition):

Chen, Hailong. “Mixed Formulation Using Implicit Boundary Finite Element Method.” 2012. Masters Thesis, University of Florida. Accessed April 16, 2021. https://ufdc.ufl.edu/UFE0044151.

MLA Handbook (7^th Edition):

Chen, Hailong. “Mixed Formulation Using Implicit Boundary Finite Element Method.” 2012. Web. 16 Apr 2021.

Vancouver:

Chen H. Mixed Formulation Using Implicit Boundary Finite Element Method. [Internet] [Masters thesis]. University of Florida; 2012. [cited 2021 Apr 16]. Available from: https://ufdc.ufl.edu/UFE0044151.

Council of Science Editors:

Chen H. Mixed Formulation Using Implicit Boundary Finite Element Method. [Masters Thesis]. University of Florida; 2012. Available from: https://ufdc.ufl.edu/UFE0044151

Louisiana State University

3. Woelke, Pawel Benedykt. Computational model for elasto-plastic and damage analysis of plates and shells.

Degree: PhD, Civil and Environmental Engineering, 2005, Louisiana State University

URL: etd-07082005-043614 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2945

► Shells and plates are very important for various engineering applications. Analysis and design of these structures is therefore continuously of interest to the scientific and… (more)

▼ Shells and plates are very important for various engineering applications. Analysis and design of these structures is therefore continuously of interest to the scientific and engineering community. Accurate and conservative assessments of the maximum load carried by the structure, as well as the equilibrium path in both elastic and inelastic range are of paramount importance. Elastic behaviour of shells has been very closely investigated, mostly by means of the finite element method. Inelastic analysis on the other hand, especially accounting for damage effects, has received much less attention from the researchers. A computational model for finite element, elasto-plastic and damage analysis of homogenous and isotropic shells is presented here. The formulation of the model proceeds in several stages, described in the following chapters. First, a theory for thick spherical shells is developed, providing a set of shell constitutive equations. These equations incorporate the effects of transverse shear deformation, initial curvature and radial stresses. The proposed shell equations are conveniently used in finite element analysis. A simple C0 quadrilateral, doubly curved shell element is developed. By means of a quasi-conforming technique shear and membrane locking are prevented. The element stiffness matrix is given explicitly which makes this formulation computationally very efficient. The elasto-plastic behavior of thick shells and plates is represented by means of the non-layered model, with an Updated Lagrangian method used to describe a small strain geometric non-linearity. In the treatment of material non-linearities an Iliushin?s yield function expressed in terms of stress resultants is adopted, with isotropic and kinematic hardening rules. Finally, the damage effects modeled through the evolution of porosity are incorporated into the yield function, giving a generalized and convenient yield surface expressed in terms of the stress resultants. Since the elastic stiffness matrix is derived explicitly, and a non-layered model is employed in which integration through the thickness is not necessary, the current stiffness matrix is also given explicitly and numerical integration is not performed at any stage during the analysis. This makes this model consistent mathematically, accurate for a variety of applications and very inexpensive from the point of view of computer power.

Subjects/Keywords: transverse shear strains; plates and shells; damage in shells; plastic shells with mixed hardening; large rotations; shear and membrane locking

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Woelke, P. B. (2005). Computational model for elasto-plastic and damage analysis of plates and shells. (Doctoral Dissertation). Louisiana State University. Retrieved from etd-07082005-043614 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2945

Chicago Manual of Style (16^th Edition):

Woelke, Pawel Benedykt. “Computational model for elasto-plastic and damage analysis of plates and shells.” 2005. Doctoral Dissertation, Louisiana State University. Accessed April 16, 2021. etd-07082005-043614 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2945.

MLA Handbook (7^th Edition):

Woelke, Pawel Benedykt. “Computational model for elasto-plastic and damage analysis of plates and shells.” 2005. Web. 16 Apr 2021.

Vancouver:

Woelke PB. Computational model for elasto-plastic and damage analysis of plates and shells. [Internet] [Doctoral dissertation]. Louisiana State University; 2005. [cited 2021 Apr 16]. Available from: etd-07082005-043614 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2945.

Council of Science Editors:

Woelke PB. Computational model for elasto-plastic and damage analysis of plates and shells. [Doctoral Dissertation]. Louisiana State University; 2005. Available from: etd-07082005-043614 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2945

4. Cinefra, Maria. Refined and advanced shell models for the analysis of advanced structures : Modèles raffinées et avancées de coque pour l'analyse des structures.

Degree: Docteur es, Mécanique, 2012, Université Paris X – Nanterre

URL: http://www.theses.fr/2012PA100051

►

La thèse est décomposée en trois parties. Dans la première partie, les modèles de la CUF sont présentés. La CUF permet d’obtenir, dans un formalisme… (more)

▼

La thèse est décomposée en trois parties. Dans la première partie, les modèles de la CUF sont présentés. La CUF permet d’obtenir, dans un formalisme générale, de nombreux modèles qui diffèrent 1) selon l’ordre d’expansion dans l'épaisseur choisie pour les variables primaires; 2) selon le type de modèle: modèles couche équivalente (ESL) ou couche discrète (LW); 3) selon le principe variationnel : “Principle of Virtual Displacements” (raffinée) ou “Reissner’s Mixed Variational Theorem” (avancée). Des géométries cylindrique et à double courbure sont traités. La deuxième partie de la thèse est consacrée à l'obtention des équations fondamentales en utilisant différentes méthodes: la méthode analytique de Navier et deux méthodes numériques approchées; la “Finite Element Method” (FEM) et la “Radial Basis Functions” (RBF). La méthode RBF est une méthode sans maillage “meshless” et peut être considérée comme une méthode alternative à la FEM. La FEM est la plus utilisée dans la littérature et le sujet principal de cette thèse.Dans la dernière partie, différents problèmes sont proposés. Navier est utilisé pour l’analyse thermomécanique de coques FGM, l’analyse de coques piézo-électrique et l’analyse dynamique de nanotubes de carbone. Un élément fini coque, présenté dans cette thèse, est utilisé pour l’analyse de coques composites et FGM. Les résultats obtenus démontrent la supériorité de cet élément par rapport aux éléments finis basés sur les théories classiques pour l’analyse des matériaux avancés. Enfin, la méthode RBF est utilisée pour l’analyse de coques composites, permettant d'illustrer l'avantage des méthodes sans maillage.

The dissertation is organized in three main parts. In the first part, the shell models contained in the CUF are presented. The CUF permits to obtain, in a general and unified manner, several models that can differ by 1) the chosen order of expansion in the thickness direction, 2) the equivalent single layer or layer wise approach and 3) the variational statement used: “Principle of Virtual Displacements” (refined models) or “Reissner’s Mixed Variational Theorem” (advanced models). Both the cylindrical and the double-curvature geometries are considered. The second part is devoted to the derivation of the governing equations by means of different methods: an analytical method, that is the Navier method, and two approximated numerical methods, that are the Finite Element Method (FEM) and the Radial Basis Functions (RBF) method. The RBF method is based on a meshless approach and it can be considered a good alternative to the FEM. The finite element method is the most common method used in literature and it is the main topic of this thesis. In the last part, different problems are analyzed. The thermo-mechanical analysis of FGM shells, the electromechanical analysis of piezoelectric shells and the dynamic analysis of carbon nanotubes are performed by means of the Navier method. Then, the CUF shell finite element, presented in this thesis, is tested and used for the analysis of composite and FGM shells.…

Advisors/Committee Members: Polit, Olivier (thesis director).

Subjects/Keywords: Coque; Modèles raffinés; Structures multicouches; Problème multi-champs; Méthode des éléments finis; Verrouillage en cisaillement et en membrane; Shell; Refined models; Multilayered structures; Multifield problems; Finite element method; Membrane and shear locking; 620

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Cinefra, M. (2012). Refined and advanced shell models for the analysis of advanced structures : Modèles raffinées et avancées de coque pour l'analyse des structures. (Doctoral Dissertation). Université Paris X – Nanterre. Retrieved from http://www.theses.fr/2012PA100051

Chicago Manual of Style (16^th Edition):

Cinefra, Maria. “Refined and advanced shell models for the analysis of advanced structures : Modèles raffinées et avancées de coque pour l'analyse des structures.” 2012. Doctoral Dissertation, Université Paris X – Nanterre. Accessed April 16, 2021. http://www.theses.fr/2012PA100051.

MLA Handbook (7^th Edition):

Cinefra, Maria. “Refined and advanced shell models for the analysis of advanced structures : Modèles raffinées et avancées de coque pour l'analyse des structures.” 2012. Web. 16 Apr 2021.

Vancouver:

Cinefra M. Refined and advanced shell models for the analysis of advanced structures : Modèles raffinées et avancées de coque pour l'analyse des structures. [Internet] [Doctoral dissertation]. Université Paris X – Nanterre; 2012. [cited 2021 Apr 16]. Available from: http://www.theses.fr/2012PA100051.

Council of Science Editors:

Cinefra M. Refined and advanced shell models for the analysis of advanced structures : Modèles raffinées et avancées de coque pour l'analyse des structures. [Doctoral Dissertation]. Université Paris X – Nanterre; 2012. Available from: http://www.theses.fr/2012PA100051

University of Washington

5. Kim, Han-Gyu. Experimental and Numerical Nonlinear Dynamics and Stress Field Analysis of Post-Buckled Composite Plates.

Degree: PhD, 2019, University of Washington

URL: http://hdl.handle.net/1773/44119

► Thermally-buckled composite panels in aircraft may experience dynamic snap-through due to aerodynamic loading, which can accelerate damage growth (or delamination) in these structures. Therefore, characterizing… (more)

▼ Thermally-buckled composite panels in aircraft may experience dynamic snap-through due to aerodynamic loading, which can accelerate damage growth (or delamination) in these structures. Therefore, characterizing post-buckled dynamic response and corresponding stress fields can be an important step to help assure the structural integrity of composite structures. To address this issue, this work experimentally and numerically investigates nonlinear dynamics and snap-through of post-buckled laminated composite plates under harmonic loading. In addition, stress fields induced by these phenomena are simulated to explore their potential impact on the fatigue failure of composite structures. The experimental investigation made in this work is intended to lead to a better fundamental understanding of the aforementioned phenomena and to provide benchmark data for robust model validation in the nonlinear regime. The dynamic response of a post-buckled composite specimen under various harmonic scenarios is captured using a full-field digital image correlation system. The spatio-temporal complexity and parameter sensitivity of the dynamic response are explored and the snap-through boundaries of the specimen are characterized. Several numerical models are built using in-house finite element codes written in MATLAB and are calibrated using the static full-field measurement of the buckled shape of the specimen. The primary objectives of the modeling done in this work are to develop reliable simulation tools for numerical analysis of nonlinear dynamics, and to investigate the impact of nonlinear dynamics and snap-through on stress fields. A model based on the classical laminated plate theory and nonconforming (semi-C1 continuity) cubic Hermite elements (free of shear locking) is shown to achieve excellent agreement with the experimental observations including the snap-through boundaries. As a ‘truth’ model in the thin plate limit, this model provides a new tool for developing benchmark data (displacement fields) for validation of computationally-demanding models which involve high computational costs or potential locking issues. For accurate and direct computation of stress fields, another model is generated based on the first-order shear deformation theory and bi-linear elements (C0 continuity). The shear and membrane locking issues of this model are exposed through linear and nonlinear analyses of its displacement and stress fields. To address these locking issues, two types of assumed strain methods are employed: the mixed interpolation of tensorial components (MITC4) and the enhanced assumed strain (EAS) method. The geometrically-nonlinear analysis presented herein shows that the EAS method effectively controls both shear and membrane locking, whereas the MITC4 method alleviates only shear locking with strong oscillations of membrane stresses which imply the occurrence of membrane locking. The simulation results obtained using the EAS model reveal that post-buckled response generates larger-amplitude stresses than the pre-buckled… Advisors/Committee Members: Wiebe, Richard (advisor).

Subjects/Keywords: Digital image correlation (DIC); Enhanced assumed strain (EAS); Mixed interpolation of tensorial components (MITC4); Nonlinear dynamics and snap-through boundaries; Shear and membrane locking; Stress and fatigue analysis of post-buckled composite plates; Aerospace engineering; Mechanical engineering; Civil engineering; Civil engineering

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Kim, H. (2019). Experimental and Numerical Nonlinear Dynamics and Stress Field Analysis of Post-Buckled Composite Plates. (Doctoral Dissertation). University of Washington. Retrieved from http://hdl.handle.net/1773/44119

Chicago Manual of Style (16^th Edition):

Kim, Han-Gyu. “Experimental and Numerical Nonlinear Dynamics and Stress Field Analysis of Post-Buckled Composite Plates.” 2019. Doctoral Dissertation, University of Washington. Accessed April 16, 2021. http://hdl.handle.net/1773/44119.

MLA Handbook (7^th Edition):

Kim, Han-Gyu. “Experimental and Numerical Nonlinear Dynamics and Stress Field Analysis of Post-Buckled Composite Plates.” 2019. Web. 16 Apr 2021.

Vancouver:

Kim H. Experimental and Numerical Nonlinear Dynamics and Stress Field Analysis of Post-Buckled Composite Plates. [Internet] [Doctoral dissertation]. University of Washington; 2019. [cited 2021 Apr 16]. Available from: http://hdl.handle.net/1773/44119.

Council of Science Editors:

Kim H. Experimental and Numerical Nonlinear Dynamics and Stress Field Analysis of Post-Buckled Composite Plates. [Doctoral Dissertation]. University of Washington; 2019. Available from: http://hdl.handle.net/1773/44119

6. Le, Thi Huyen Cham. Robust variable kinematics plate ﬁnite elements for composite structures : Éléments finis robustes à cinématique variable pour la modélisation des plaques composites.

Degree: Docteur es, Mécanique, génie mécanique, génie civil, 2019, Université Paris X – Nanterre

URL: http://www.theses.fr/2019PA100053

►

Le but de ce travail est de développer deux nouveaux éléments ﬁnis quadrilatéraux à quatre et à huit nœuds implantés dans le code commercial de… (more)

▼

Le but de ce travail est de développer deux nouveaux éléments ﬁnis quadrilatéraux à quatre et à huit nœuds implantés dans le code commercial de calcul par Eléments Finis (EF) Abaqus pour plaques composites. Les modèles plaques à cinématique variable sont formulés dans le cadre de la formulation uniﬁée de Carrera (CUF), qui regroupent des descriptions de type: couche équivalente (ESL) et couches discrètes (LW), avec les variables déﬁnies par des polynômes jusqu’au 4ème ordre suivant épaisseur z. Les deux formulations variationnelles sont utilisées pour dériver les matrices des éléments ﬁnis: le Principe des Déplacements Virtuels (PVD) et le Théorème Variationnel Mixte de Reissner (RMVT). Grâce à la technique de condensation statique, une formulation hybride basée sur le RMVT est introduite. Aﬁn d’éliminer la pathologie de verrouillage en cisaillement transverse, deux approximations compatibles pour le champ de déformations de cisaillement transverse indépendantes en z, notée QC4 et CL8, sont étendues aux éléments plaques à cinématique variable basés sur CUF. De plus, les QC4S et CL8S interpolations sont également introduites pour les contraintes de cisaillement transverse dans les éléments mixtes et les éléments hybrides. Les résultats numériques comparés à ceux disponibles dans la littérature montrent que les FE proposés sont eﬃcaces pour modéliser des éléments ﬁnis robustes.

The aim of this work is the development of two classes of new four-node and eightnode quadrilateral ﬁnite elements implemented into the commercial ﬁnite element (FE) code Abaqus for composite plates. Variable kinematics plate models are formulated in the framework of Carrera’s Uniﬁed Formulation (CUF), which encompasses Equivalent Single Layer (ESL) as well as Layer-Wise (LW) models, with the variables that are deﬁned by polynomials up to 4th order along the thickness direction z. The two classes refer to two variational formulations that are employed to derive the ﬁnite elements matrices, namely the Principle of Virtual Displacement (PVD) and Reissner’s Mixed Variational Theorem (RMVT). Thanks to the static condensation technique, a Hybrid formulation based on the RMVT is derived. For the purpose of eliminating the shear locking pathology, two ﬁeld compatible approximations for only the z−constant transverse shear strain terms, referred to as QC4 and CL8 interpolations, are extended to all variable kinematics CUF plate elements. Moreover, the QC4S and CL8S interpolations, are also introduced for the transverse shear stress ﬁeld within RMVT-based and Hybrid mixed-based elements. Numerical results in comparison with those available in literature show that the proposed FEs are eﬃcient for modeling a robust ﬁnite elements.

Advisors/Committee Members: Polit, Olivier (thesis director).

Subjects/Keywords: Cinématique variable; Verrouillage en cisaillement transverse; Maillage distordu; Eléments Finis plaque; Structure composite; Plaque trouée; Plate finite element; Variable kinematics model; Shear locking; Mesh distortion; Composite structure; Plate with hole; 621

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Le, T. H. C. (2019). Robust variable kinematics plate ﬁnite elements for composite structures : Éléments finis robustes à cinématique variable pour la modélisation des plaques composites. (Doctoral Dissertation). Université Paris X – Nanterre. Retrieved from http://www.theses.fr/2019PA100053

Chicago Manual of Style (16^th Edition):

Le, Thi Huyen Cham. “Robust variable kinematics plate ﬁnite elements for composite structures : Éléments finis robustes à cinématique variable pour la modélisation des plaques composites.” 2019. Doctoral Dissertation, Université Paris X – Nanterre. Accessed April 16, 2021. http://www.theses.fr/2019PA100053.

MLA Handbook (7^th Edition):

Le, Thi Huyen Cham. “Robust variable kinematics plate ﬁnite elements for composite structures : Éléments finis robustes à cinématique variable pour la modélisation des plaques composites.” 2019. Web. 16 Apr 2021.

Vancouver:

Le THC. Robust variable kinematics plate ﬁnite elements for composite structures : Éléments finis robustes à cinématique variable pour la modélisation des plaques composites. [Internet] [Doctoral dissertation]. Université Paris X – Nanterre; 2019. [cited 2021 Apr 16]. Available from: http://www.theses.fr/2019PA100053.

Council of Science Editors:

Le THC. Robust variable kinematics plate ﬁnite elements for composite structures : Éléments finis robustes à cinématique variable pour la modélisation des plaques composites. [Doctoral Dissertation]. Université Paris X – Nanterre; 2019. Available from: http://www.theses.fr/2019PA100053

7. Wobker, Hilmar. Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems.

Degree: 2010, Technische Universität Dortmund

URL: http://hdl.handle.net/2003/26998

► Bei der Simulation realistischer strukturmechanischer Probleme können Gleichungssysteme mit mehreren hundert Millionen Unbekannten entstehen. Für die effiziente Lösung solcher Systeme sind parallele Multilevel-Methoden unerlässlich, die… (more)

▼ Bei der Simulation realistischer strukturmechanischer Probleme können Gleichungssysteme mit mehreren hundert Millionen Unbekannten entstehen. Für die effiziente Lösung solcher Systeme sind parallele Multilevel-Methoden unerlässlich, die in der Lage sind, die Leistung moderner Hardware-Technologien auszuschöpfen. Die Finite-Elemente- und Löser-Toolbox FEAST, die auf die Behandlung skalarer Gleichungen ausgelegt ist, verfolgt genau dieses Ziel. FEAST kombiniert Hardware-orientierte Implementierungstechniken mit einer Multilevel-Gebietszerlegungsmethode namens ScaRC. In der vorliegenden Arbeit wird ein Konzept entwickelt, multivariate Elastizitätsprobleme basierend auf der FEAST-Bibliothek zu lösen. Die generelle Herangehensweise besteht darin, die Lösung multivariater Probleme auf die Lösung einer Reihe von skalaren Problemen zurückzuführen. Dieser Ansatz ermöglicht eine strikte Trennung von skalaren "low level" Kernfunktionalitäten (in Form der FEAST-Bibliothek) und multivariatem "high level" Anwendungscode (in Form des Elastizitätsproblems), was aus Sicht der Softwareentwicklungstechnik sehr vorteilhaft ist: Alle Bemühungen zur Verbesserung der Hardware-Effizienz, sowie Anpassungen an zukünftige technologische Entwicklungen können auf skalare Operationen beschränkt werden, während die multivariate Anwendung automatisch von diesen Erweiterungen profitiert. Im ersten Teil der Arbeit werden substantielle Verbesserungen der skalaren ScaRC-Löser entwickelt, die dann als essentielle Bausteine zur Lösung multivariater Elastizitätsprobleme eingesetzt werden. Ausführliche numerische Untersuchungen zeigen, wie sich die Effizienz der skalaren FEAST-Bibliothek auf den multivariaten Lösungsprozess überträgt. Die Löserstrategie wird dann auf nichtlineare Probleme der Elastizität mit finiter Deformation angewandt. Durch Einsatz einer Liniensuche-Methode wird die Robustheit des Newton-Raphson-Verfahrens signifikant erhöht. Es werden verschiedene Strategien miteinander verglichen, wie genau die linearen Probleme innerhalb der nichtlinearen Iteration zu lösen sind. Zur Behandlung der wichtigen Klasse von (fast) inkompressiblen Materialien wird eine gemischte Verschiebung/Druck-Formulierung gewählt, die mit Hilfe von stabilisierten bilinearen finiten Elementen (Q1/Q1) diskretisiert wird. Eine erweiterte Version der klassischen "Druck-Poisson"-Stabilisierung wird präsentiert, die auch für hochgradig irreguläre Gitter geeignet ist. Es werden Vor- und Nachteile der Q1/Q1-Diskretisierung erörtert, insbesondere in Bezug auf zeitabhängige Rechnungen. Zwei Löser-Klassen zur Behandlung der entstehenden Sattelpunkt-Probleme werden beschrieben und miteinander verglichen: einerseits verschiedene Arten von (beschleunigten) entkoppelten Lösern (Uzawa, Druck-Schurkomplement-Methoden, Block-Vorkonditionierer), andererseits gekoppelte Mehrgitter-Verfahren mit Vanka-Glättern. Effiziente Schurkomplement-Vorkonditionierer, die für die erste Löser-Klasse notwendig sind, werden im Rahmen statischer und zeitabhängiger Probleme besprochen. Die zentrale… Advisors/Committee Members: Turek, S..

Subjects/Keywords: Adaptive coarse grid correction; Adaptive Grobgitterkorrektur; Damped Newton-Raphson; Domain decomposition; Elasticity; Elastizität; Elastodynamic; Elastodynamisch; Elastostatic; Elastostatisch; Equal-order finite elements; FEAST; FEAST; Festkörpermechanik; Finite deformation; Finite Deformation; Finite-Elemente-Methode; Finite element method; Gebietszerlegung; Gedämpftes Newton-Raphson; Gemischte Formulierung; Globales Newton-Raphson; Global Newton-Raphson; Große Deformation; Großskalig; Hardware-oriented; Hardware-orientiert; High performance computing; Incompressible material; Inexact Newton-Raphson; Inexaktes Newton-Raphson; Inkompressibles Material; Irreguläres Gitter; Irregular grids; Iterativer Löser; Iterative solver; Large deformation; Large-scale; LBB stabilisation; LBB Stabilisierung; Line-search; Liniensuche; Mehrgitter; Mehrgitter-Krylov; Minimale Überlappung; Minimal overlap; Mixed formulation; Multigrid; Multigrid-Krylov; Multilevel; Multilevel; Newton-Raphson; Nicht-konformes Mehrgitter; Nonconforming multigrid; Parallel computing; Parallele Effizienz; Parallel efficiency; Paralleles Rechnen; Saddle point problem; Sattelpunkt-Problem; ScaRC; ScaRC; Schubversteifung; Schur complement preconditioning; Schurkomplement-Vorkonditionierer; Shear locking; Solid mechanics; Structural mechanics; Strukturmechanik; Transient; Vanka; Vanka; Volume locking; Volumenversteifung; Zeitabhängig; 510

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wobker, H. (2010). Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems. (Thesis). Technische Universität Dortmund. Retrieved from http://hdl.handle.net/2003/26998

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Wobker, Hilmar. “Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems.” 2010. Thesis, Technische Universität Dortmund. Accessed April 16, 2021. http://hdl.handle.net/2003/26998.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Wobker, Hilmar. “Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems.” 2010. Web. 16 Apr 2021.

Vancouver:

Wobker H. Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems. [Internet] [Thesis]. Technische Universität Dortmund; 2010. [cited 2021 Apr 16]. Available from: http://hdl.handle.net/2003/26998.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wobker H. Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems. [Thesis]. Technische Universität Dortmund; 2010. Available from: http://hdl.handle.net/2003/26998

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

8. Wobker, Hilmar. Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems.

Degree: 2010, Technische Universität Dortmund

URL: http://dx.doi.org/10.17877/DE290R-497

► In the simulation of realistic solid mechanical problems, linear equation systems with hundreds of million unknowns can arise. For the efficient solution of such systems,… (more)

▼ In the simulation of realistic solid mechanical problems, linear equation systems with hundreds of million unknowns can arise. For the efficient solution of such systems, parallel multilevel methods are mandatory that are able to exploit the capabilities of modern hardware technologies. The finite element and solution toolbox FEAST, which is designed to solve scalar equations, pursues exactly this goal. It combines hardware-oriented implementation techniques with a multilevel domain decomposition method called ScaRC that achieves high numerical and parallel efficiency. In this thesis a concept is developed to solve multivariate elasticity problems based on the FEAST library. The general strategy is to reduce the solution of multivariate problems to the solution of a series of scalar problems. This approach facilitates a strict separation of 'low level' scalar kernel functionalities (in the form of the FEAST library) and 'high level' multivariate application code (in the form of the elasticity problem), which is very attractive from a software-engineering point of view: All efforts to improve hardware-efficiency and adaptations to future technology trends can be restricted to scalar operations, and the multivariate application automatically benefits from these enhancements. In the first part of the thesis, substantial improvements of the scalar ScaRC solvers are developed, which are then used as essential building blocks for the efficient solution of multivariate elasticity problems. Extensive numerical studies demonstrate how the efficiency of the scalar FEAST library transfers to the multivariate solution process. The solver strategy is then applied to treat nonlinear problems of finite deformation elasticity. A line-search method is used to significantly increase the robustness of the Newton-Raphson method, and different strategies are compared how to choose the accuracy of the linear system solves within the nonlinear iteration. In order to treat the important class of (nearly) incompressible material, a mixed displacement/pressure formulation is used which is discretised with stabilised bilinear finite elements (Q1/Q1). An enhanced version of the classical 'pressure Poisson' stabilisation is presented which is suitable for highly irregular meshes. Advantages and disadvantages of the Q1/Q1 discretisation are discussed, especially in the context of transient computations. Two solver classes for the resulting saddle point systems are described and compared: on the one hand various kinds of (accelerated) segregated solvers (Uzawa, pressure Schur complement methods, block preconditioners), and on the other hand coupled multigrid solvers with Vanka-smoothers. Efficient Schur complement preconditioners, which are required for the former class, are discussed for the static and the transient case. The main strategy to reduce the solution of multivariate systems to the solution of scalar systems is only applicable in the case of segregated methods. It is shown that for the class of elasticity problems considered in this… Advisors/Committee Members: Turek, S. (advisor), Suttmeier, F.-T. (referee).

Subjects/Keywords: Iterativer Löser; Multilevel; Mehrgitter; Gebietszerlegung; Mehrgitter-Krylov; Nicht-konformes Mehrgitter; ScaRC; Adaptive Grobgitterkorrektur; Minimale Überlappung; Sattelpunkt-Problem; Schurkomplement-Vorkonditionierer; Vanka; Gedämpftes Newton-Raphson; Globales Newton-Raphson; Inexaktes Newton-Raphson; Liniensuche; FEAST; Hardware-orientiert; Großskalig; Paralleles Rechnen; Parallele Effizienz; Finite-Elemente-Methode; Gemischte Formulierung; LBB Stabilisierung; Irreguläres Gitter; Festkörpermechanik; Strukturmechanik; Elastizität; Elastostatisch; Elastodynamisch; Zeitabhängig; Inkompressibles Material; Finite Deformation; Große Deformation; Volumenversteifung; Schubversteifung; Iterative solver; Multilevel; Multigrid; Domain decomposition; Multigrid-Krylov; Nonconforming multigrid; ScaRC; Adaptive coarse grid correction; Minimal overlap; Saddle point problem; Schur complement preconditioning; Vanka; Newton-Raphson; Damped Newton-Raphson; Global Newton-Raphson; Inexact Newton-Raphson; Line-search; FEAST; High performance computing; Hardware-oriented; Large-scale; Parallel computing; Parallel efficiency; Finite element method; Mixed formulation; LBB stabilisation; Equal-order finite elements; Irregular grids; Solid mechanics; Structural mechanics; Elasticity; Elastostatic; Elastodynamic; Transient; Incompressible material; Finite deformation; Large deformation; Volume locking; Shear locking; 510

Record Details Similar Records Cite « Share

❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wobker, H. (2010). Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems. (Doctoral Dissertation). Technische Universität Dortmund. Retrieved from http://dx.doi.org/10.17877/DE290R-497

Chicago Manual of Style (16^th Edition):

Wobker, Hilmar. “Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems.” 2010. Doctoral Dissertation, Technische Universität Dortmund. Accessed April 16, 2021. http://dx.doi.org/10.17877/DE290R-497.

MLA Handbook (7^th Edition):

Wobker, Hilmar. “Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems.” 2010. Web. 16 Apr 2021.

Vancouver:

Wobker H. Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems. [Internet] [Doctoral dissertation]. Technische Universität Dortmund; 2010. [cited 2021 Apr 16]. Available from: http://dx.doi.org/10.17877/DE290R-497.

Council of Science Editors:

Wobker H. Efficient multilevel solvers and high performance computing techniques for the finite element simulation of large-scale elasticity problems. [Doctoral Dissertation]. Technische Universität Dortmund; 2010. Available from: http://dx.doi.org/10.17877/DE290R-497

		in
And / Or
		in
And / Or
		in
And / Or
		in

Open Access Theses and Dissertations