Castillo / Fernandez-Canteli A Unified Statistical Methodology for Modeling Fatigue Damage

1. Auflage 2009
ISBN: 978-1-4020-9182-7
Verlag: Springer Netherlands
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 232 Seiten

This book is an attempt to provide a uni?ed methodology to derive models for fatigue life. This includes S-N, ?-N and crack propagation models. This is not a conventional book aimed at describing the fatigue fundamentals, but rather a book in which the basic models of the three main fatigue approaches, the stress-based, the strain-based and the fracture mechanics approaches, are contemplated from a novel and integrated point of view. On the other hand, as an alternative to the preferential attention paid to deterministic models based on the physical, phenomenological and empirical description of fatigue, their probabilistic nature is emphasized in this book, in which stochastic fatigue and crack growth models are presented. This book is the result of a long period of close collaborationbetween its two authors who, although of di?erent backgrounds, mathematical and mechanical, both have a strong sense of engineering with respect to the fatigue problem. When the authors of this book ?rst approached the fatigue ?eld in 1982 (twenty six years ago), they found the following scenario: 1. Linear, bilinear or trilinear models were frequently proposed by relevant laboratoriesandacademiccenterstoreproducetheW¨ ohler?eld. Thiswas the case of well known institutions, which justi?ed these models based on clientrequirementsorpreferences. Thisledtotheinclusionofsuchmodels and methods as, for example, the up-and-down, in standards and o?cial practical directives (ASTM, Euronorm, etc.), which have proved to be unfortunate.

Autoren/Hrsg.

Castillo, Enrique

Fernandez-Canteli, Alfonso

Inhaltsverzeichnis

1;I Introduction and Motivation of the Fatigue Problem;14
1.1;An Overview of Fatigue Problems;15
1.1.1;Introduction;16
1.1.2;Models with dimensionless variables;16
1.1.3;S-N or Wöhler curves;18
1.1.3.1;Compatibility condition of N*| and |N*;21
1.1.3.2;Statistical considerations;23
1.1.4;-N curves;24
1.1.5;Stress level effect;25
1.1.5.1;Compatibility condition of S-N curves for constant m* and S-N curves for constant M*;26
1.1.6;Crack growth curves;28
1.1.6.1;Crack growth curves for a constant stress pair T*;30
1.1.6.2;Crack growth curves for a varying stress pair T*;32
1.1.6.3;Compatibility of crack growth and S-N models;34
1.1.7;Crack growth rate curves;34
1.1.8;Size effect;37
1.1.9;Normalization;38
1.1.9.1;Percentile based normalizations;38
1.1.9.2;Stress range and lifetime based normalizations;41
1.1.9.3;Extended percentile normalization;42
1.1.10;Damage measures and damage accumulation;43
2;II Models Used in the Stress Based Approach;45
2.1;S-N or Wöhler Field Models;46
2.1.1;Introduction;47
2.1.2;Dimensional analysis;49
2.1.3;Extreme models in fatigue;52
2.1.3.1;The Weibull model;52
2.1.3.2;The minimal Gumbel model;53
2.1.4;Model for constant stress range and level;54
2.1.4.1;Derivation of the model;54
2.1.4.2;Parameter estimation;56
2.1.4.3;Alternative methods for dealing with run-outs;59
2.1.5;Model for varying range and given stress level;60
2.1.5.1;Derivation of the model;60
2.1.5.2;Some weaknesses of the proposed model;64
2.1.5.3;Parameter estimation;66
2.1.5.4;Use of the model in practice;67
2.1.5.5;Example of application;68
2.1.6;Model for varying stress range and level;70
2.1.7;Dimensional Weibull and Gumbel models;75
2.1.8;Properties of the model;76
2.1.8.1;Parameter estimation;80
2.1.8.2;Use of the model in practice;82
2.1.8.3;Example of applications;83
2.1.9;Concluding remarks;95
2.1.10;Appendix A: Derivation of the general model;96
2.1.11;Appendix B: S-N curves for the general model;100
2.2;Length Effect;102
2.2.1;Introduction;102
2.2.2;Modeling the S-N field for different lengths;106
2.2.2.1;A previous example;106
2.2.2.2;General model for different lengths;108
2.2.2.3;Parameter estimation;109
2.2.3;Examples of Application;111
2.2.3.1;Prestressing wires;111
2.2.3.2;Prestressing strands;116
3;III Models Used in the Strain Based Approach;121
3.1;Log-Weibull -N Model;122
3.1.1;Introduction;122
3.1.2;Model for constant strain range and level;125
3.1.2.1;Practical example;128
3.1.3;Model for varying strain range and level;128
3.1.4;Converting strain- into stress-life curves;130
3.1.4.1;Practical example;132
3.1.5;Concluding remarks;133
4;IV Models Used in the Fracture Mechanics Approach;135
4.1;Crack Growth Models;136
4.1.1;Introduction and motivation;136
4.1.2;Building crack growth models;138
4.1.3;Crack growth curves approach I;142
4.1.3.1;Crack growth curves for constant * and *;142
4.1.3.2;Crack growth curves for varying * and *;145
4.1.3.3;Compatibility of crack growth and S-N models;148
4.1.4;Crack growth curves approach II;151
4.1.4.1;Crack growth curves for constant * and *;151
4.1.4.2;Crack growth curves for varying * and *;153
4.1.4.3;Statistical distributions of a*|N* and N*|a*;156
4.1.4.4;Learning and estimating the model;159
4.1.4.5;Compatibility of approaches I and II;160
4.1.5;Example of application;161
4.1.6;Summary and future work;163
5;V Damage and Damage Accumulation Models;165
5.1;Damage Measures;166
5.1.1;Introduction;166
5.1.2;Normalization;170
5.1.3;Damage measures;172
5.1.3.1;Some requirements for a damage measure;172
5.1.3.2;Some damage measures;173
5.1.4;Concluding remarks;179
5.2;Damage Accumulation;180
5.2.1;Damage accumulation;180
5.2.1.1;Accumulated damage after a constant stress range load step;185
5.2.1.2;Accumulated damage after block loading;186
5.2.1.3;Fatigue under a general loading history;187
5.2.1.4;Random loading;191
5.2.2;Crack growth damage for any load history;191
6;VI Appendices;195
6.1;Models Used in Fatigue;196
6.1.1;Introduction;196
6.1.2;S-N curve models;199
6.1.2.1;The Wöhler model;199
6.1.2.2;The Basquin model;201
6.1.2.3;The Strohmeyer model;202
6.1.2.4;The Palmgren model;202
6.1.2.5;The Stüssi model;203
6.1.2.6;The Weibull model;203
6.1.2.7;The Spindel and Haibach model;203
6.1.2.8;The Kohout and Vechet model;204
6.1.3;Stress field models;205
6.1.3.1;The Pascual and Meeker model;205
6.1.3.2;The Bastenaire model;205
6.1.3.3;The Castillo et al. (1985) model;207
6.1.4;Fatigue limit models;208
6.1.4.1;The up-and-down method;208
6.2;Notation Used in This Book;216
6.3;Bibliography;216
6.4;Index;222