Modellierung des thermo-mechanischen Verbundverhaltens von Asphalt in Straßenaufbauten
21 Dec 2011-
TL;DR: In der vorliegenden Arbeit wird ein Verbundmodell zur Beschreibung des thermo-mechanischen Verhaltens von Asphaltmischungen entwickelt and validiert as discussed by the authors.
Abstract: In der vorliegenden Arbeit wird ein Verbundmodell zur Beschreibung des thermo-mechanischen Verhaltens von Asphaltmischungen entwickelt und validiert. Das Modell beschreibt das Materialverhalten von Asphalt als Verbundwerkstoff auf Basis der Mischungstheorie. Hierfur ist das
Verformungsverhalten der Bindemittelkomponente mit einem fraktionalen rheologischen Modell beschrieben. Die Mineralstoffkomponente wird mit einem Modell der Hypoplastizitat erfasst. Mit Hilfe einer Evolutionsstrategie erfolgt die Identifikation der Modellparameter der Einzelkomponenten auf der Grundlage experimenteller Untersuchungen. Fur die Validierung des Verbundmodells liegt ein umfangreiches experimentelles Programm vor, bei dem zwei ausgewahlte Asphaltmischungen in einaxialen Versuchen untersucht werden. Der Vergleich der Versuche mit Ergebnissen numerischer Simulationen bedingt physikalisch begrundete Modifikationen am Verbundmodell. Das modifizierte Modell ermoglicht die Analyse des Verformungsverhaltens realer Strukturen aus Asphaltmaterialien in numerischen Berechnungen mit der Finite-Element-Methode.
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TL;DR: In this article, Zener uses the term "anelasticity" to describe the properties of solids, as a result of which stress and strain are not uniquely related.
Abstract: WHEN metals are submitted to stress, the stress/swain relation is generally regarded as consisting of two parts, the elastic region and the region bfsplastiwin which a permanent set remains upon the remova of the stress. In the elastic region the absence of a permanent set does not necessarily imply that the relation between stress and strain is linear of even single-valued. Prof. Zener uses the term ‘anelasticity’ to describe the properties of solids, as a result of which stress and strain are not uniquely related. Examples are the elastic after-effect, the dependence of elastic constants on the method of measurement, and the dissipation of energy during vibration, which is often referred to as the damping capacity or internal friction of a solid. These effects have aroused much interest in recent years, largely owing to Prof. Zener's own work, and a good book on the subject is much to be desired. Elasticity and Anelasticity of Metals By Clarence Zener. Pp. x + 170. (Chicago: University of Chicago Press, London: Cambridge University Press, 1948.) 4 dollars.
235 citations
Journal Article•
TL;DR: The paper presents the hypoplastic model that is capable of capturing the salient features of granular materials for problems involving extremely low stress levels or extremely high stress.
Abstract: A hypoplastic constitutive model and hypoplasticity are described briefly.A procedure for the determination of its parameters is described in detail.This model is based on nonlinear tensorial functions and is developed without recourse to concepts of elastoplasticity theory such as yield surface,plastic potential,flow and hardening rules and decomposition of deformation into elastic and plastic parts.The paper also presents the hypoplastic model that is capable of capturing the salient features of granular materials,in particular,for problems involving extremely low stress levels or extremely high stress.
27 citations
TL;DR: In this paper, the structural long-term response of asphalt pavements (modeled as elastoplastic solid at large strains) under periodic traffic load is investigated within the finite element method (FEM).
26 citations
23 Nov 2007
TL;DR: In this article, a generalised DARCY model for multiphase transport of municipal solid waste is proposed to describe the motion of the pore fluids, and structural analyses using the finite element method identify risks concerning the stability of landfill structures.
Abstract: The present thesis deals with modelling and simulation of the deformation behaviour of municipal solid waste. Municipal solid waste is a porous medium, in which landfill gas and leachate can move freely in the pore space. The Theory of Porous Media is the continuum mechanical framework for the model development. The applied kinematics are nonlinear because large displacements and deformations have to be described. The solid material consists of a basic matrix with properties similar to granular materials, in which fibrous constituents are embedded. Constitutive relations for the two solid phases include spontaneous as well as time-dependent inelastic behaviour. Effects from the anisotropic orientation of the fibres are considered, too. A generalised DARCY model for multiphase transport describes the motion of the pore fluids. Numerical simulations of laboratory experiments validate and verify the model. Structural analyses using the finite element method identify risks concerning the stability of landfill structures. The transport equations are simultaneously solved by the box method, a special case of the finite volume method.
7 citations
TL;DR: In this paper, a physically motivated continuum mechanical model for asphalt concrete and stone mastic asphalt (asphalt material) at large deformations is proposed, which consists of a short-term and a long-term part connected in series governing the description of the shortterm and the longterm behavior of the asphalt material, respectively.
5 citations
References
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TL;DR: In this paper, a method of calculating the average internal stress in the matrix of a material containing inclusions with transformation strain is presented. But the authors do not consider the effects of the interaction among the inclusions and of the presence of the free boundary.
7,000 citations
"Modellierung des thermo-mechanische..." refers background in this paper
...Die Homogenisierung der Steifigkeiten und der thermischen Eigenschaften von einer Betrachtungsebene zur nächst höheren erfolgt mit dem Modell von MORI/TANAKA [83]....
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Book•
12 Sep 2000
TL;DR: In this paper, the authors present a list of boxes for Lagrangian and Eulerian Finite Elements in One Dimension (LDF) in one dimension, including Beams and Shells.
Abstract: Preface. List of Boxes. Introduction. Lagrangian and Eulerian Finite Elements in One Dimension. Continuum Mechanics. Lagrangian Meshes. Constitutive Models Solution Methods and Stability. Arbitrary Lagrangian Eulerian Formulations. Element Technology. Beams and Shells. Contact--Impact. Appendix 1: Voigt Notation. Appendix 2: Norms. Appendix 3: Element Shape Functions. Glossary. References. Index.
3,928 citations
"Modellierung des thermo-mechanische..." refers background in this paper
...: Zum mechanischen Verhalten granularer Stoffe unter vorwiegend ödometrischer Beanspruchung, Institut für Bodenmechanik und Felsmechanik der Universität Karlsruhe, Dissertation, 1992 [8] BELYTSCHKO, T....
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3,423 citations
"Modellierung des thermo-mechanische..." refers background in this paper
...2 im Vergleich zu den bekannteren Fließflächen nach MOHR/COULOMB [20] und DRUCKER/PRAGER [32] dargestellt....
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Book•
01 Jan 1987TL;DR: This second edition has been updated and expanded to cover recent developments in applications and theory, including an elegant NP completeness argument by Uwe Naumann and a brief introduction to scarcity, a generalization of sparsity.
Abstract: Algorithmic, or automatic, differentiation (AD) is a growing area of theoretical research and software development concerned with the accurate and efficient evaluation of derivatives for function evaluations given as computer programs. The resulting derivative values are useful for all scientific computations that are based on linear, quadratic, or higher order approximations to nonlinear scalar or vector functions. AD has been applied in particular to optimization, parameter identification, nonlinear equation solving, the numerical integration of differential equations, and combinations of these. Apart from quantifying sensitivities numerically, AD also yields structural dependence information, such as the sparsity pattern and generic rank of Jacobian matrices. The field opens up an exciting opportunity to develop new algorithms that reflect the true cost of accurate derivatives and to use them for improvements in speed and reliability. This second edition has been updated and expanded to cover recent developments in applications and theory, including an elegant NP completeness argument by Uwe Naumann and a brief introduction to scarcity, a generalization of sparsity. There is also added material on checkpointing and iterative differentiation. To improve readability the more detailed analysis of memory and complexity bounds has been relegated to separate, optional chapters.The book consists of three parts: a stand-alone introduction to the fundamentals of AD and its software; a thorough treatment of methods for sparse problems; and final chapters on program-reversal schedules, higher derivatives, nonsmooth problems and iterative processes. Each of the 15 chapters concludes with examples and exercises. Audience: This volume will be valuable to designers of algorithms and software for nonlinear computational problems. Current numerical software users should gain the insight necessary to choose and deploy existing AD software tools to the best advantage. Contents: Rules; Preface; Prologue; Mathematical Symbols; Chapter 1: Introduction; Chapter 2: A Framework for Evaluating Functions; Chapter 3: Fundamentals of Forward and Reverse; Chapter 4: Memory Issues and Complexity Bounds; Chapter 5: Repeating and Extending Reverse; Chapter 6: Implementation and Software; Chapter 7: Sparse Forward and Reverse; Chapter 8: Exploiting Sparsity by Compression; Chapter 9: Going beyond Forward and Reverse; Chapter 10: Jacobian and Hessian Accumulation; Chapter 11: Observations on Efficiency; Chapter 12: Reversal Schedules and Checkpointing; Chapter 13: Taylor and Tensor Coefficients; Chapter 14: Differentiation without Differentiability; Chapter 15: Implicit and Iterative Differentiation; Epilogue; List of Figures; List of Tables; Assumptions and Definitions; Propositions, Corollaries, and Lemmas; Bibliography; Index
2,920 citations
"Modellierung des thermo-mechanische..." refers background in this paper
...Die mathematischen Hintergründe und die numerische Umsetzung der algorithmischen Differentiation sind ausführlich in GRIEWANK/WALTHER [40] dargestellt....
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TL;DR: The fundamental assumption of all theories of plasticity, that of time independence of the equations of state, makes simultaneous description of the plastic and rheologic properties of a material impossible as mentioned in this paper.
Abstract: Publisher Summary The fundamental assumption of all theories of plasticity—that of time independence of the equations of state—makes simultaneous description of the plastic and rheologic properties of a material impossible. I t is well-known that in many practical problems, the actual behaviour of a material is governed by plastic as well as by rheologic effects. It can even be said that for many important structural materials, rheologic effects are more pronounced after the plastic state has been reached. Every material shows more or less pronounced viscous properties. In some problems, the influence of viscous properties of the material may be negligible, while in others, it may be essential. Both sciences—plasticity and rheology—are concerned with the description of important mechanical properties of structural materials. Each of them has created its own methods of investigation and has developed within the framework of certain assumptions which, unfortunately, cannot always be satisfied in reality. The results of rheology are confined to cases where plastic strain is of no decisive importance.
1,672 citations
"Modellierung des thermo-mechanische..." refers background in this paper
...[105] und LU/WRIGHT [79], welche die visko-plastischen Dehnungsanteile mit Hilfe einer assoziierten Fließregel unter Verwendung eines Ansatzes von PERZYNA [93] ermitteln....
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