Page 18 - T. Anderson-Fracture Mechanics - Fundamentals and Applns.-CRC (2005)

1656_FM.fm Page xvi Tuesday, May 3, 2005 5:49 PM

8.3 Ceramics ...............................................................................................................................378
8.3.1 Chevron-Notched Specimens ...................................................................................378
8.3.2 Bend Specimens Precracked by Bridge Indentation ...............................................380
References ......................................................................................................................................382
Chapter 9
Application to Structures ...............................................................................................................385
9.1 Linear Elastic Fracture Mechanics.......................................................................................385
9.1.1 K for Part-Through Cracks......................................................................................387
I
9.1.2 Influence Coefficients for Polynomial Stress Distributions ....................................388
9.1.3 Weight Functions for Arbitrary Loading .................................................................392
9.1.4 Primary, Secondary, and Residual Stresses .............................................................394
9.1.5 A Warning about LEFM...........................................................................................395
9.2 The CTOD Design Curve ....................................................................................................395
9.3 Elastic-Plastic J-Integral Analysis........................................................................................397
9.3.1 The EPRI J-Estimation Procedure...........................................................................398
9.3.1.1 Theoretical Background ............................................................................398
9.3.1.2 Estimation Equations.................................................................................399
9.3.1.3 Comparison with Experimental J Estimates.............................................401
9.3.2 The Reference Stress Approach...............................................................................403
9.3.3 Ductile Instability Analysis......................................................................................405
9.3.4 Some Practical Considerations.................................................................................408
9.4 Failure Assessment Diagrams ..............................................................................................410
9.4.1 Original Concept ......................................................................................................410
9.4.2 J-Based FAD ............................................................................................................412
9.4.3 Approximations of the FAD Curve..........................................................................415
9.4.4 Estimating the Reference Stress...............................................................................416
9.4.5 Application to Welded Structures ............................................................................423
9.4.5.1 Incorporating Weld Residual Stresses.......................................................423
9.4.5.2 Weld Misalignment....................................................................................426
9.4.5.3 Weld Strength Mismatch...........................................................................427
9.4.6 Primary vs. Secondary Stresses in the FAD Method ..............................................428
9.4.7 Ductile-Tearing Analysis with the FAD...................................................................430
9.4.8 Standardized FAD-Based Procedures ......................................................................430
9.5 Probabilistic Fracture Mechanics.........................................................................................432
Appendix 9: Stress Intensity and Fully Plastic J Solutions
for Selected Configurations ...................................................................................434
References ......................................................................................................................................449

Chapter 10
Fatigue Crack Propagation.............................................................................................................451
10.1 Similitude in Fatigue ..........................................................................................................451
10.2 Empirical Fatigue Crack Growth Equations ......................................................................453
10.3 Crack Closure .....................................................................................................................457
10.3.1 A Closer Look at Crack-Wedging Mechanisms...................................................460
10.3.2 Effects of Loading Variables on Closure..............................................................463
10.4 The Fatigue Threshold........................................................................................................464
10.4.1 The Closure Model for the Threshold..................................................................465
10.4.2 A Two-Criterion Model.........................................................................................466
10.4.3 Threshold Behavior in Inert Environments ..........................................................470
10.5 Variable Amplitude Loading and Retardation....................................................................473