Residual Strength and Fatigue Lifetime of ... - Solid Mechanics
Residual Strength and Fatigue Lifetime of ... - Solid Mechanics Residual Strength and Fatigue Lifetime of ... - Solid Mechanics
Published in Denmark by Technical University of Denmark Copyright © Ramin Moslemian 2011 All rights reserved Section of Coastal, Maritime and Structural Engineering Department of Mechanical Engineering Technical University of Denmark Nils Koppels Alle, Building 403, DK-2800 Kgs. Lyngby, Denmark Phone +45 4525 1360, Telefax +45 4588 4325 Email: info.skk@mek.dtu.dk WWW: http://www.mek.dtu.dk Publication Reference Data Moslemian, R. Residual Strength and Fatigue Lifetime of Debond Damaged Sandwich Structures PhD Thesis Technical University of Denmark, Section of Coastal, Maritime and Structural Engineering September 2011 ISBN 978-87-90416-73-7 Keywords: Fatigue, Fracture, Sandwich Structures, Composite Materials, Debonding
Preface This thesis is submitted as a partial fulfillment of the requirements for the Danish Ph.D. degree. The work was conducted at the Section of Coastal, Maritime and Structural Engineering, Department of Mechanical Engineering, Technical University of Denmark, during the period from January 2008 to September 2011. The project was supervised by Associate Professor Christian Berggreen, Professor Leif A. Carlsson, Senior Scientist Bent F. Sørensen and Senior Scientist Kim Branner. My sincere thanks go to Associated Professor Christian Berggreen for his supervision during the entire project, encouragement, and many illuminating discussions about different topics from practical matters regarding the experiments to theoretical discussions about fracture mechanics. His support and guidance is highly appreciated. Many thanks to Professor Leif A. Carlsson from Florida Atlantic University, for his insightful comments and constructive criticism. Special thanks go to Assistant Professor Amilcar Quispitupa at the Department of Mechanical Engineering, DTU for interesting discussions and priceless helps during the experiments. I am further grateful to Professor Jørgen Juncher Jensen, head of the Section of Coastal, Maritime and Structural Engineering, Department of Mechanical Engineering, DTU for facilitating a friendly trouble-free atmosphere at the working environment and to other colleagues at the Department as well. Part of this thesis was conducted abroad during seven months at the Department of Mechanical Engineering, University of Delaware, USA under the supervision of Professor Anette Karlsson. I would like to thank Anette for all her guidance, and for introducing the cycle jump technique to me which is the main foundation under the second part of this thesis. Very special thanks go to Professor Brian Hayman from Department of Mathematics, University of Oslo, Norway (earlier at Det Norske Veritas) for providing test specimens and precious discussions. Thanks to PhD candidate Marcello Manca and MSc student Sota Sugimoto for helping me with conducting fatigue experiments. Finally my very special thanks go to Leila for being there for me and her support during the last years of the study. i
- Page 1: Residual Strength and Fatigue Lifet
- Page 6 and 7: This page is intentionally left bla
- Page 8 and 9: method to accelerate the simulation
- Page 10 and 11: Synopsis Sandwich kompositter er i
- Page 12 and 13: This page is intentionally left bla
- Page 14 and 15: Contents Preface Executive Summary
- Page 16 and 17: 5 Face/core Interface Fatigue Crack
- Page 18 and 19: This page is intentionally left bla
- Page 20 and 21: H11 bimaterial constant H22 bimater
- Page 22 and 23: This page is intentionally left bla
- Page 24 and 25: These peculiar damage modes often r
- Page 26 and 27: 1.2 Overview of the Thesis In this
- Page 28 and 29: Figure 1.3: Fracture modes, from Be
- Page 30 and 31: In Equations (1.5) and (1.6) H11, H
- Page 32 and 33: Figure 1.6: Schematic illustration
- Page 34 and 35: The compact tension specimen (CT) i
- Page 36 and 37: A Figure 1.10: CSB, DCB, TSD, DCB-U
- Page 38 and 39: Chapter 2 Buckling Driven Face/Core
- Page 40 and 41: (DIC) measurement system (ARAMIS 2M
- Page 42 and 43: corresponds to the onset of debond
- Page 44 and 45: Figure 2.7: Crack kinking into the
- Page 46 and 47: (2.2) where and for plane str
- Page 48 and 49: A modified version of the tilted sa
- Page 50 and 51: previous observations of crack path
- Page 52 and 53: of contact elements (CONTACT173 and
Preface<br />
This thesis is submitted as a partial fulfillment <strong>of</strong> the requirements for the Danish Ph.D. degree.<br />
The work was conducted at the Section <strong>of</strong> Coastal, Maritime <strong>and</strong> Structural Engineering,<br />
Department <strong>of</strong> Mechanical Engineering, Technical University <strong>of</strong> Denmark, during the period<br />
from January 2008 to September 2011. The project was supervised by Associate Pr<strong>of</strong>essor<br />
Christian Berggreen, Pr<strong>of</strong>essor Leif A. Carlsson, Senior Scientist Bent F. Sørensen <strong>and</strong> Senior<br />
Scientist Kim Branner.<br />
My sincere thanks go to Associated Pr<strong>of</strong>essor Christian Berggreen for his supervision during the<br />
entire project, encouragement, <strong>and</strong> many illuminating discussions about different topics from<br />
practical matters regarding the experiments to theoretical discussions about fracture mechanics.<br />
His support <strong>and</strong> guidance is highly appreciated. Many thanks to Pr<strong>of</strong>essor Leif A. Carlsson from<br />
Florida Atlantic University, for his insightful comments <strong>and</strong> constructive criticism. Special<br />
thanks go to Assistant Pr<strong>of</strong>essor Amilcar Quispitupa at the Department <strong>of</strong> Mechanical<br />
Engineering, DTU for interesting discussions <strong>and</strong> priceless helps during the experiments. I am<br />
further grateful to Pr<strong>of</strong>essor Jørgen Juncher Jensen, head <strong>of</strong> the Section <strong>of</strong> Coastal, Maritime <strong>and</strong><br />
Structural Engineering, Department <strong>of</strong> Mechanical Engineering, DTU for facilitating a friendly<br />
trouble-free atmosphere at the working environment <strong>and</strong> to other colleagues at the Department as<br />
well.<br />
Part <strong>of</strong> this thesis was conducted abroad during seven months at the Department <strong>of</strong> Mechanical<br />
Engineering, University <strong>of</strong> Delaware, USA under the supervision <strong>of</strong> Pr<strong>of</strong>essor Anette Karlsson. I<br />
would like to thank Anette for all her guidance, <strong>and</strong> for introducing the cycle jump technique to<br />
me which is the main foundation under the second part <strong>of</strong> this thesis. Very special thanks go to<br />
Pr<strong>of</strong>essor Brian Hayman from Department <strong>of</strong> Mathematics, University <strong>of</strong> Oslo, Norway (earlier<br />
at Det Norske Veritas) for providing test specimens <strong>and</strong> precious discussions. Thanks to PhD<br />
c<strong>and</strong>idate Marcello Manca <strong>and</strong> MSc student Sota Sugimoto for helping me with conducting<br />
fatigue experiments.<br />
Finally my very special thanks go to Leila for being there for me <strong>and</strong> her support during the last<br />
years <strong>of</strong> the study.<br />
i