Analyse visco-plastique de l'endommagement des plaques et coques soumises aux impacts, Viscoplastic damage analysis of plate-shell structures subjected to impact loading

Lukasz Pyrzowski

Description

Sous la direction de Krzysztof Woznica, Pawel Klosowski
Thèse soutenue le 26 novembre 2010: Université de Gdansk, Orléans
Le travail concerne le comportement des plaques et coques soumises à des charges dynamiques dues à des explosions des mélanges gazeux. Des problèmes mécaniques d’apparition des fissures et d’endommagement ductile sont analysés. En introduction, la revue de la littérature a été présentée ainsi que les théories actuellement les plus souvent utilisées dans ce domaine. Une brève description des outils numériques qui ont servi dans l’étude a été également donnée. Les essais expérimentaux et les résultats des mesures ont été discutés dans la deuxième partie du mémoire. Ils ont permis d’identifier les paramètres matériels du modèle constitutif viscoplastique et d’endommagement nécessaires pour mener une analyse numérique du comportement des plaques, de faire la vérification des nombreuses simulations discutées à la fin du travail. Dans les conclusions, est présenté le bilan des modélisations en exposant surtout celles qui ont conduit à de meilleurs résultats.L’auteur discute les hypothèses utilisées, les limitations du modèle et esquisse desperspectives et l’évolution possible à l’avenir.
-Lois de comportement
-Dynamique des plaques
The work presents the investigation in the response of plate-shell structures subjected to impact loadings (gas mixture explosions). This phenomenon is studied in the context of its mechanical aspects, mainly the ductile fracture prediction. The work starts with the literature review and the description of theories, which are nowadays the most popular in the damage and fracture modelling. After selecting the theoretical models and the numerical tools for the further analysis, the detailed report of all realized experimental tests and their results ispresented. Then, for the assumed constitutive and damage laws, the identification of material and fracture criteria parameters is realized. Finally, the numerical simulations are performed and their results, verified by the experiments, are summarized and commented.The work finishes with the conclusions, where the best approaches (from those, which havebeen tested) are pointed, all assumptions or limitations used in the study are discussed and the objectives for the further research are indicated.
-Fracture modelling
-Plates under impact loadings
Source: http://www.theses.fr/2010ORLE2035/document

Informations

• Publié par: Thesee
• Nombre de lectures: 22
• Langue: English
• Poids de l'ouvrage: 22 Mo

Extrait

ÉCOLE DOCTORALE SCIENCES ET TECHNOLOGIE

Institut PRISME / Faculty of Civil and Environmental Engineering
THÈSE EN COTUTELLE INTERNATIONALE présentée par:
ukasz PYRZOWSKI
soutenue le: 26 novembre 2010
pour obtenir le grade de:
Docteur de l’Université d’Orléans
et de l’Ecole Polytechnique de Gdansk
Discipline: Génie mécanique
ANALYSE VISCO-PLASTIQUE DE L’ENDOMMAGEMENT
DES PLAQUES ET COQUES SOUMISES AUX IMPACTS
VISCOPLASTIC DAMAGE ANALYSIS OF PLATE-SHELL
STRUCTURES SUBJECTED TO IMPACT LOADING
THÈSE dirigée par:
M. Krzysztof WOZNICA Professeur, ENSI de Bourges
M. Pawe K!OSOWSKI Professeur, Ecole Polytechnique de Gdansk
RAPPORTEURS:
M. Ryszard P"CHERSKI Professeur, Institute of Fundamental
Technological Research, Polish Academy of
Sciences
M. Géry DE SAXCÉ Professeur, Université Sciences et Technologies
de Lille
_____________________________________________________________________
JURY:
M. Bogdan ZADROGA Professeur, Ecole Polytechnique de Gdansk
Président du jury
M. Ryszard P"CHERSKI Professeur, Institute of Fundamental
Technological Research, Polish Academy of
Sciences
M. Géry DE SAXCÉ Professeur, Université Sciences et Technologies
de Lille
M. Krzysztof WOZNICA Professeur, ENSI de Bourges
M. Pawe K!OSOWSKI Professeur, Ecole Polytechnique de Gdansk
tel-00608054, version 1 - 12 Jul 2011tel-00608054, version 1 - 12 Jul 2011
Acknowledgements
The author is extremely grateful to supervisors prof. Pawe K osowski and prof. Krzysztof
Woznica for care and introducing to the world of scientific research. He appreciates all long
discussions and remarks, which have made creating of this work possible.
Special thanks are addressed to prof. Krzysztof Woznica for the warmly welcoming in
Bourges and to Olivier Pennetier for all his help during realization of the laboratory test
program.
The author would like to thank prof. Jacek Chró!cielewski for all accurate remarks and
comments.
All presented numerical simulations were performed by computers of the Academic
Computer Centre in Gdansk (CI TASK).
Finally, the author thanks his dear family and friends for their faith and support.
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Contents
1. Introduction ............................................................................................................... - 9 -
1.1. Foreword .................................................................................................................. - 9 -
1.2. Aim and range .......................................................................................................... - 9 -
1.3. Literature review .................................................................................................... - 10 -
2. Theoretical foundations .......................................................................................... - 21 -
2.1. Abstract .................................................................................................................. - 21 -
2.2. Introduction ............................................................................................................ - 21 -
2.3. Constitutive model ................................................................................................. - 21 -
2.4. Damage and fracture models .................................................................................. - 23 -
2.4.1. Fracture mechanics .......................................................................................... - 23 -
2.4.2. Continuum damage mechanics ........................................................................ - 27 -
2.4.3. Porous solid plasticity models ......................................................................... - 32 -
2.4.4. Abrupt failure criteria ...................................................................................... - 33 -
2.5. Summary ................................................................................................................ - 37 -
3. Numerical tools ........................................................................................................ - 39 -
3.1. Abstract .................................................................................................................. - 39 -
3.2. Introduction ............................................................................................................ - 39 -
3.3. Elements selected for numerical analyses .............................................................. - 39 -
3.4. Large displacement analysis .................................................................................. - 42 -
3.5. User-defined subroutines ....................................................................................... - 44 -
3.6. Integration of the motion equation ......................................................................... - 47 -
3.7. Contact phenomena ................................................................................................ - 48 -
3.8. Adaptive mesh ........................................................................................................ - 49 -
3.9. Summary ................................................................................................................ - 50 -
4. Experimental tests ................................................................................................... - 51 -
4.1. Abstract .................................................................................................................. - 51 -
4.2. Introduction ............................................................................................................ - 51 -
4.3. Experiments on plates ............................................................................................ - 51 -
4.3.1. Research stand and experimental devices ....................................................... - 52 -
4.3.2. Experimental work in dynamic tests ............................................................... - 53 -
4.3.3. Results of dynamic experiments ...................................................................... - 55 -
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4.3.4. Experimental work in quasi-static test ............................................................. - 61 -
4.3.5. Result of quasi-static experiment ..................................................................... - 62 -
4.4. Uniaxial experiments .............................................................................................. - 62 -
4.4.1. Tension tests with constant strain rates ............................................................ - 63 -
4.4.2. Load-unload tension cyclic tests ...................................................................... - 63 -
4.5. Summary ................................................................................................................. - 64 -
5. Material parameters identification ......................................................................... - 65 -
5.1. Abstract ................................................................................................................... - 65 -
5.2. Introduction ............................................................................................................ - 65 -
5.3. Identification of elastic modulus and yield stress ................................................... - 66 -
5.4. Identification of Chaboche model parameters ........................................................ - 68 -
5.5. Verification of material parameters identification .................................................. - 74 -
5.6. Identification of damage and its model material parameters .................................. - 77 -
5.6.1. Damage measurement method ......................................................................... - 77 -
5.6.2. Damage measurement, first approach .............................................................. - 79 -
5.6.3. Identification of model material parameters for first damage approach .......... - 80 -
5.6.4. Verification of first approach damage material parameters identification ...... - 82 -
5.6.5. Damage measurement, second approach ......................................................... - 83 -
5.6.6. Verification of second approach damage material parameters identification .. - 88 -
5.7. Summary ................................................................................................................. - 89 -
6. Fracture criteria calibration ................................................................................... - 91 -
6.1. Abstract ................................................................................................................... - 91 -
6.2. Introduction ............................................................................................................ - 91 -
6.3. Critical equivalent plastic strain criterion ............................................................... - 92 -
6.4. Total strain energy density criterion ....................................................................... - 92 -
6.5. Stress triaxiality ratio based cri