TY - CHAP
A1 - Most, Thomas
A1 - Eckardt, Stefan
A1 - Schrader, Kai
A1 - Deckner, T.
ED - Gürlebeck, Klaus
ED - Könke, Carsten
T1 - AN IMPROVED COHESIVE CRACK MODEL FOR COMBINED CRACK OPENING AND SLIDING UNDER CYCLIC LOADING
N2 - The modeling of crack propagation in plain and reinforced concrete structures is still a field for many researchers. If a macroscopic description of the cohesive cracking process of concrete is applied, generally the Fictitious Crack Model is utilized, where a force transmission over micro cracks is assumed. In the most applications of this concept the cohesive model represents the relation between the normal crack opening and the normal stress, which is mostly defined as an exponential softening function, independently from the shear stresses in tangential direction. The cohesive forces are then calculated only from the normal stresses. By Carol et al. 1997 an improved model was developed using a coupled relation between the normal and shear damage based on an elasto-plastic constitutive formulation. This model is based on a hyperbolic yield surface depending on the normal and the shear stresses and on the tensile and shear strength. This model also represents the effect of shear traction induced crack opening. Due to the elasto-plastic formulation, where the inelastic crack opening is represented by plastic strains, this model is limited for applications with monotonic loading. In order to enable the application for cases with un- and reloading the existing model is extended in this study using a combined plastic-damage formulation, which enables the modeling of crack opening and crack closure. Furthermore the corresponding algorithmic implementation using a return mapping approach is presented and the model is verified by means of several numerical examples. Finally an investigation concerning the identification of the model parameters by means of neural networks is presented. In this analysis an inverse approximation of the model parameters is performed by using a given set of points of the load displacement curves as input values and the model parameters as output terms. It will be shown, that the elasto-plastic model parameters could be identified well with this approach, but require a huge number of simulations.
KW - Architektur
KW - CAD
KW - Computerunterstütztes Verfahren
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29933
UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
ER -
TY - CHAP
A1 - Most, Thomas
ED - Gürlebeck, Klaus
ED - Könke, Carsten
T1 - ESTIMATING UNCERTAINTIES FROM INACCURATE MEASUREMENT DATA USING MAXIMUM ENTROPY DISTRIBUTIONS
N2 - Modern engineering design often considers uncertainties in geometrical and material parameters and in the loading conditions. Based on initial assumptions on the stochastic properties as mean values, standard deviations and the distribution functions of these uncertain parameters a probabilistic analysis is carried out. In many application fields probabilities of the exceedance of failure criteria are computed. The out-coming failure probability is strongly dependent on the initial assumptions on the random variable properties. Measurements are always more or less inaccurate data due to varying environmental conditions during the measurement procedure. Furthermore the estimation of stochastic properties from a limited number of realisation also causes uncertainties in these quantities. Thus the assumption of exactly known stochastic properties by neglecting these uncertainties may not lead to very useful probabilistic measures in a design process. In this paper we assume the stochastic properties of a random variable as uncertain quantities caused by so-called epistemic uncertainties. Instead of predefined distribution types we use the maximum entropy distribution which enables the description of a wide range of distribution functions based on the first four stochastic moments. These moments are taken again as random variables to model the epistemic scatter in the stochastic assumptions. The main point of this paper is the discussion on the estimation of these uncertain stochastic properties based on inaccurate measurements. We investigate the bootstrap algorithm for its applicability to quantify the uncertainties in the stochastic properties considering imprecise measurement data. Based on the obtained estimates we apply standard stochastic analysis on a simple example to demonstrate the difference and the necessity of the proposed approach.
KW - Angewandte Informatik
KW - Angewandte Mathematik
KW - Architektur
KW - Computerunterstütztes Verfahren
KW - Computer Science Models in Engineering; Multiscale and Multiphysical Models; Scientific Computing
Y1 - 2010
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28732
UR - http://euklid.bauing.uni-weimar.de/ikm2009/paper.html
SN - 1611-4086
ER -
TY - CHAP
A1 - Most, Thomas
T1 - An adaptive response surface approach for structural reliability analyses based on support vector machines
N2 - An adaptive response surface approach for structural reliability analyses based on support vector machines
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2007
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Eckardt, Stefan
A1 - Schrader, Kai
A1 - Deckner, T.
T1 - An improved cohesive crack model for combined crack opening and sliding under cyclic loading
N2 - An improved cohesive crack model for combined crack opening and sliding under cyclic loading
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2006
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Eckardt, Stefan
T1 - Application of a hybrid parallelisation technique to accelerate the numerical simulation of nonlinear mechanical problems
N2 - Application of a hybrid parallelisation technique to accelerate the numerical simulation of nonlinear mechanical problems
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2004
ER -
TY - CHAP
A1 - Most, Thomas
T1 - Anwendung netzfreier Diskretisierungsverfahren zur stochastischen Rissfortschrittsberechnung
N2 - Anwendung netzfreier Diskretisierungsverfahren zur stochastischen Rissfortschrittsberechnung
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2003
ER -
TY - CHAP
A1 - Brehm, Maik
A1 - Most, Thomas
T1 - A four-node plane EAS-element for stochastic nonlinear materials
N2 - A four-node plane EAS-element for stochastic nonlinear materials
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2003
ER -
TY - CHAP
A1 - Most, Thomas
T1 - An adaptive response surface approach for reliability analyses of high-dimensional problems
N2 - An adaptive response surface approach for reliability analyses of high-dimensional problems
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2008
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Hofstetter, G.
A1 - Hofmann, Markus
A1 - Novák, D.
A1 - Lehký, D.
T1 - Approximation of constitutive parameters for material models using artificial neural networks
N2 - Approximation of constitutive parameters for material models using artificial neural networks
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2007
ER -
TY - JOUR
A1 - Most, Thomas
T1 - A natural neighbour-based moving least-squares approach for the element-free Galerkin method
JF - International Journal for Numerical Methods in Engineering
N2 - A natural neighbour-based moving least-squares approach for the element-free Galerkin method
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2007
SP - 224
EP - 252
ER -
TY - CHAP
A1 - Brehm, Maik
A1 - Most, Thomas
T1 - A Four-Node Plane EAS-Element for Stochastic Nonlinear Materials
N2 - Iso-parametric finite elements with linear shape functions show in general a too stiff element behavior, called locking. By the investigation of structural parts under bending loading the so-called shear locking appears, because these elements can not reproduce pure bending modes. Many studies dealt with the locking problem and a number of methods to avoid the undesirable effects have been developed. Two well known methods are the >Assumed Natural Strain< (ANS) method and the >Enhanced Assumed Strain< (EAS) method. In this study the EAS method is applied to a four-node plane element with four EAS-parameters. The paper will describe the well-known linear formulation, its extension to nonlinear materials and the modeling of material uncertainties with random fields. For nonlinear material behavior the EAS parameters can not be determined directly. Here the problem is solved by using an internal iteration at the element level, which is much more efficient and stable than the determination via a global iteration. To verify the deterministic element behavior the results of common test examples are presented for linear and nonlinear materials. The modeling of material uncertainties is done by point-discretized random fields. To show the applicability of the element for stochastic finite element calculations Latin Hypercube Sampling was applied to investigate the stochastic hardening behavior of a cantilever beam with nonlinear material. The enhanced linear element can be applied as an alternative to higher-order finite elements where more nodes are necessary. The presented element formulation can be used in a similar manner to improve stochastic linear solid elements.
KW - Nichtlineare Mechanik
KW - Finite-Elemente-Methode
KW - Zufallsvariable
Y1 - 2003
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2825
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Ishii, H.
A1 - Geng, X.
A1 - Bolzern, P.
A1 - Colaneri, P.
A1 - De Nicolao, G.
T1 - Discussion on Almost sure stability of stochastic linear systems with ergodic parameters
JF - European Journal of Control
N2 - Discussion on Almost sure stability of stochastic linear systems with ergodic parameters
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2008
SP - 124
EP - 130
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Eckardt, Stefan
T1 - Application of a hybrid parallelization technique to accelerate the numerical simulation of nonlinear mechanical problems
N2 - This paper presents the combination of two different parallelization environments, OpenMP and MPI, in one numerical simulation tool. The computation of the system matrices and vectors is parallelized with OpenMP and the solution of the system of equations is done with the MPIbased solver MUMPS. The efficiency of both algorithms is shown on several linear and nonlinear examples using the Finite Element Method and a meshless discretization technique.
KW - Framework
KW - API
KW - Parallelverarbeitung
KW - Finite-Elemente-Methode
Y1 - 2004
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-2599
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Energy-based simulation of concrete cracking using an improved mixed-mode cohesive crack model within a meshless discretization
JF - International Journal for Numerical and Analytical Methods in Geomechanics
N2 - Energy-based simulation of concrete cracking using an improved mixed-mode cohesive crack model within a meshless discretization
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2007
SP - 285
EP - 305
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Unger, Jörg F.
A1 - Bucher, Christian
T1 - Stochastic crack growth simulation in R/C structures by means of meshless methods
N2 - Stochastic crack growth simulation in R/C structures by means of meshless methods
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2005
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - A moving least squares weighting function for the element-free Galerkin method which almost fulfills essential boundary conditions
JF - Structural Engineering and Mechanics
N2 - A moving least squares weighting function for the element-free Galerkin method which almost fulfills essential boundary conditions
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2005
SP - 315
EP - 332
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Stochastic dynamic stability analysis for nonlinear structures
N2 - Stochastic dynamic stability analysis for nonlinear structures
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2002
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Unger, Jörg F.
A1 - Bucher, Christian
T1 - Stochastic modeling of cohesive crack propagation using meshless discretization techniques
N2 - Stochastic modeling of cohesive crack propagation using meshless discretization techniques
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2004
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Stochastic modeling of cohesive crack evolution in concrete using meshless interpolation techniques
N2 - Stochastic modeling of cohesive crack evolution in concrete using meshless interpolation techniques
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2004
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Stochastic simulation of cracking in concrete structures using multi-parameter random fields
JF - International Journal of Reliability and Safety
N2 - Stochastic simulation of cracking in concrete structures using multi-parameter random fields
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2006
SP - 168
EP - 187
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Probabilistic analysis of concrete cracking using neural networks and random fields
JF - Probabilistic Engineering Mechanics
N2 - Probabilistic analysis of concrete cracking using neural networks and random fields
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2007
SP - 219
EP - 229
ER -
TY - JOUR
A1 - Kirichuk, A.
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Numerical nonlinear analysis of kinematically excited shells
JF - International Journal for Computational Civil and Structural Engineering
N2 - Numerical nonlinear analysis of kinematically excited shells
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2003
SP - 61
EP - 74
ER -
TY - CHAP
A1 - Schorling, York
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Stability Analysis for Imperfect Systems with Random Loading
N2 - Stability Analysis for Imperfect Systems with Random
Loading
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2001
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
A1 - Macke, M.
ED - Gürlebeck, Klaus
ED - Könke, Carsten
T1 - A NATURAL NEIGHBOR BASED MOVING LEAST SQUARES APPROACH WITH INTERPOLATING WEIGHTING FUNCTION
N2 - The Element-free Galerkin Method has become a very popular tool for the simulation of mechanical problems with moving boundaries. The internally applied Moving Least Squares approximation uses in general Gaussian or cubic weighting functions and has compact support. Due to the approximative character of this method the obtained shape functions do not fulfill the interpolation condition, which causes additional numerical effort for the imposition of the essential boundary conditions. The application of a singular weighting function, which leads to singular coefficient matrices at the nodes, can solve this problem, but requires a very careful placement of the integration points. Special procedures for the handling of such singular matrices were proposed in literature, which require additional numerical effort. In this paper a non-singular weighting function is presented, which leads to an exact fulfillment of the interpolation condition. This weighting function leads to regular values of the weights and the coefficient matrices in the whole interpolation domain even at the nodes. Furthermore this function gives much more stable results for varying size of the influence radius and for strongly distorted nodal arrangements than classical weighting function types. Nevertheless, for practical applications the results are similar as these obtained with the regularized weighting type presented by the authors in previous publications. Finally a new concept will be presented, which enables an efficient analysis of systems with strongly varying node density. In this concept the nodal influence domains are adapted depending on the nodal configuration by interpolating the influence radius for each direction from the distances to the natural neighbor nodes. This approach requires a Voronoi diagram of the domain, which is available in this study since Delaunay triangles are used as integration background cells. In the numerical examples it will be shown, that this method leads to a more uniform and reduced number of influencing nodes for systems with varying node density than the classical circular influence domains, which means that the small additional numerical effort for interpolating the influence radius leads to remarkable reduction of the total numerical cost in a linear analysis while obtaining similar results. For nonlinear calculations this advantage would be even more significant.
KW - Architektur
KW - CAD
KW - Computerunterstütztes Verfahren
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29943
UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Bucher, Christian
A1 - Schorling, York
T1 - Dynamic stability analysis of non-linear structures with geometrical imperfections under random loading
JF - Journal of Sound and Vibration
N2 - Dynamic stability analysis of non-linear structures with geometrical imperfections under random loading
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2004
SP - 381
EP - 400
ER -
TY - JOUR
A1 - Bucher, Christian
A1 - Most, Thomas
T1 - A comparison of approximate response functions in structural reliability analysis
JF - Probabilistic Engineering Mechanics
N2 - A comparison of approximate response functions in structural reliability analysis
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2008
SP - 154
EP - 163
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Mixed mode crack simulation using Virtual Crack Extension and a normal/shear cohesive crack model within a meshless discretization
N2 - Mixed mode crack simulation using Virtual Crack Extension and a normal/shear cohesive crack model within a meshless discretization
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2005
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Adaptive response surface approach using artificial neural networks and Moving Least Squares
N2 - Adaptive response surface approach using artificial neural networks and Moving Least Squares
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2006
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Moving Least Squares-elements for stochastic crack propagation simulations coupled with stochastic finite elements
N2 - Moving Least Squares-elements for stochastic crack propagation simulations coupled with stochastic finite elements
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2003
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Application of the "fictious crack model" to meshless crack growth simulations
N2 - In this paper a meshless component is presented, which internally uses the common meshless interpolation technique >Moving Least Squares<. In contrast to usual meshless integration schemes like the cell quadrature and the nodal integration in this study integration zones with triangular geometry spanned by three nodes are used for 2D analysis. The boundary of the structure is defined by boundary nodes, which are similar to finite element nodes. By using the neighborhood relations of the integration zones an efficient search algorithm to detected the nodes in the influence of the integration points was developed. The components are directly coupled with finite elements by using a penalty method. An widely accepted model to describe the fracture behavior of concrete is the >Fictitious Crack Model< which is applied in this study, which differentiates between micro cracks and macro cracks, with and without force transmission over the crack surface, respectively. In this study the crack surface is discretized by node pairs in form of a polygon, which is part of the boundary. To apply the >Fictitious Crack Model< finite interface elements are included between the crack surface nodes. The determination of the maximum principal strain at the crack tip is done by introducing an influence area around the singularity. On a practical example it is shown that the included elements improve the model by the transmission of the surface forces during monotonic loading and by the representation of the contact forces of closed cracks during reverse loading.
KW - Bruchmechanik
KW - Rissbildung
KW - Modellierung
Y1 - 2003
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-3359
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
ED - Gürlebeck, Klaus
ED - Könke, Carsten
T1 - ADAPTIVE RESPONSE SURFACE APPROACH USING ARTIFICIAL NEURAL NETWORKS AND MOVING LEAST SQUARES
N2 - In engineering science the modeling and numerical analysis of complex systems and relations plays an important role. In order to realize such an investigation, for example a stochastic analysis, in a reasonable computational time, approximation procedure have been developed. A very famous approach is the response surface method, where the relation between input and output quantities is represented for example by global polynomials or local interpolation schemes as Moving Least Squares (MLS). In recent years artificial neural networks (ANN) have been applied as well for such purposes. Recently an adaptive response surface approach for reliability analyses was proposed, which is very efficient concerning the number of expensive limit state function evaluations. Due to the applied simplex interpolation the procedure is limited to small dimensions. In this paper this approach is extended for larger dimensions using combined ANN and MLS response surfaces for evaluating the adaptation criterion with only one set of joined limit state points. As adaptation criterion a combination by using the maximum difference in the conditional probabilities of failure and the maximum difference in the approximated radii is applied. Compared to response surfaces on directional samples or to plain directional sampling the failure probability can be estimated with a much smaller number of limit state points.
KW - Architektur
KW - CAD
KW - Computerunterstütztes Verfahren
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170327-29922
UR - http://euklid.bauing.uni-weimar.de/ikm2006/index.php_lang=de&what=papers.html
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Application of an adaptive response surface approach for efficient structural reliability analysis
N2 - Application of an adaptive response surface approach for efficient structural reliability analysis
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2006
ER -
TY - CHAP
A1 - Bucher, Christian
A1 - Most, Thomas
T1 - Application of approximate response functions in structural reliability analysis
N2 - Application of approximate response functions in structural reliability analysis
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2006
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Stochastic dynamic stability analysis of shell structures
N2 - Stochastic dynamic stability analysis of shell structures
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2005
ER -
TY - JOUR
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - New concepts for moving least squares: An interpolating non-singular weighting function and weighted nodal least squares
JF - Engineering Analysis with Boundary Elements
N2 - New concepts for moving least squares: An interpolating non-singular weighting function and weighted nodal least squares
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2008
SP - 461
EP - 470
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - An enhanced moving least squares interpolation for the element-free Galerkin method
N2 - An enhanced moving least squares interpolation for the element-free Galerkin method
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2006
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Application of the "Fictitious Crack Model" to meshless crack growth simulations
N2 - Application of the "Fictitious Crack Model" to meshless crack growth simulations
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2003
ER -
TY - CHAP
A1 - Unger, Jörg F.
A1 - Most, Thomas
A1 - Bucher, Christian
A1 - Könke, Carsten
T1 - Adaptation of the natural element method for crack growth simulations
N2 - Adaptation of the natural element method for crack growth simulations
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2004
ER -
TY - THES
A1 - Most, Thomas
T1 - Stochastic crack growth simulation in reinforced concrete structures by means of coupled finite element and meshless methods
N2 - The complex failure process of concrete structures can not be described in detail by standard engineering design formulas. The numerical analysis of crack development in concrete is essential for several problems. In the last decades a large number of research groups have dealt with this topic and several models and algorithms were developed. However, most of these methods show some difficulties and are limited to special cases. The goal of this study was to develop an automatic algorithm for the efficient simulation of multiple cracking in plain and reinforced concrete structures of medium size. For this purpose meshless methods were used to describe the growth of crack surfaces. Two meshless interpolation schemes were improved for a simple application. The cracking process of concrete has been modeled using a stable criterion for crack growth in combination with an improved cohesive crack model which can represent the failure process under combined crack opening and crack sliding very well. This crack growth algorithm was extended in order to represent the fluctuations of the concrete properties by enlarging the single-parameter random field concept for multiple correlated material parameters.
N2 - Das komplexe Versagensverhalten von Betonstrukturen kann in der Regel nicht mit Standardbemessungsformeln beschrieben werden. Eine detaillierte numerische Analyse der Rissentwicklung in Beton ist für einige Problemstellungen unverzichtbar. In den letzten Jahrzehnten haben sich eine Vielzahl von Forschergruppen mit dieser Thematik aus-einandergesetzt. Dabei wurden verschiedene Modelle und Algorithmen entwickelt. Die meisten dieser Verfahren weisen jedoch verschiedene Probleme auf oder sind nur für Spezialfälle anwendbar. Das Ziel dieser Arbeit war die Entwicklung eines automatischen Algorithmus zur effizienten Simulation von mehrfacher Rissentwicklung in Beton- und Stahlbetonstrukturen mittlerer Größe. Dabei wurden netzfreie Verfahren angewendet, um die Änderung der Rissoberflächen abzubilden. Zwei netzfreie Interpolationstypen wurden im Hinblick auf eine unkomplizierte Anwendung angepaßt. Der Versagensprozess des Betons wurde mit Hilfe eines stabilen Risskriteriums in Kombination mit einem erwei-terten kohäsiven Rissmodell abgebildet. Dieses erweiterte Modell kann die Zusammenhänge bei kombinierter Rissöffnung und -gleitung sehr gut wiedergeben. Der entwickelte Algorithmus zur Risssimulation wurde in Hinblick auf eine stochastische Modellierung erweitert. Zu diesem Zweck wurde das Zufallsfeldkonzept für die Abbildung mehrerer untereinander korrelierter Materialparameter ergänzt.
T2 - Stochastische Rissfortschrittsberechnung in bewehrten Betonstrukturen unter Kopplung der Finiten Elemente Methode mit netzfreien Verfahren
KW - Gitterfreie Methode
KW - Stochastik
KW - Risssimulation
KW - Stahlbeton
KW - Meshless method
KW - stochastic
KW - crack simulation
KW - reinforced concrete
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20051219-7623
ER -
TY - CHAP
A1 - Most, Thomas
A1 - Bucher, Christian
T1 - Adaptive response surface approach for reliability analysis using advanced meta-models
N2 - Adaptive response surface approach for reliability analysis using advanced meta-models
KW - Angewandte Mathematik
KW - Strukturmechanik
Y1 - 2007
ER -