Fracture Toughness of Engineering Materials: Estimation and Application
Kim Wallin
2011
ISBN 978-0-9552994-6-9 | 543 PAGES | £95 (FESI MEMBERS 10% OFF)
SHIPPING £15 p&p (UK), £55 p&p (WORLDWIDE)
Professor Kim Wallin is a recognised expert in the field of fracture mechanics. Indeed his work has provided a major input to the currently accepted ASTM Standard on the Master Curve Method, E1921. This method facilitates characterisation of ductile to brittle fracture for ferritic steels. The book was written during Wallin’s five year tenure as an Academy Professor funded by the Academy of Finland, and provides an authoritative guide and practical handbook for advanced students, fracture mechanics practitioners and R&D specialists.
The publication should provide an aid to both fracture mechanics experts and those engineers and scientists who use fracture mechanics in their daily work. It also offers an insight for the standards that need to be developed in the area of structural integrity methodologies. The intention is also to challenge and inspire the scientific experts in the field to develop possibly competing and improved fracture mechanics solutions, because fracture mechanics is still, by and large, a maturing discipline.
Chapter 1: Introduction
1.1 Background
1.2 This book
1.3 The case of the Titanic
1.4 Brittle vs ductile
1.5 Structural materials
1.6 References
Chapter 2: Fracture Mechanical Parameters
2.1 General
2.2 Crack driving force parameters
2.3 Definitions of fracture toughness
2.4 References
Chapter 3: Testing of Bend Specimens
3.1 General
3.2 The compact tension C(T) specimen
3.3 Single-edged bend specimen SE(B)
3.4 Quality assurance
3.5 References
Chapter 4: Brittle Fracture Toughness (the Master Curve)
4.1 General
4.2 Statistical modelling of cleavage fracture initiation: derivation of the Master Curve (MC) probability distribution
4.3 MC scatter
4.4 The MC statistical size
4.5 Temperature dependence of Kmin
4.6 Temperature dependence of K0
4.7 Measuring capacity of bend specimens for brittle fracture toughness testing
4.8 Effect of prior stable crack extension on cleavage fracture probability
4.9 Pre-fatigue requirements of brittle fracture toughness testing
4.10 Analysis of inhomogeneous materials
4.11 References
Chapter 5: Ductile Fatigue Toughness
5.1 General
5.2 Tearing resistance curve expressions
5.3 Scatter in ductile tearing resistance
5.4 Effect of side-grooving
5.5 Measuring capacity of bend specimens
5.6 Extrapolation of tearing resistance curves
5.7 Temperature dependence of ductile tearing resistance
5.8 The effect of mixed mode loading on the tearing resistance
5.9 References
Chapter 6: Loading Rate Effects and Crack Arrest
6.1 General
6.2 Effect of loading rate
6.3 Crack arrest toughness
6.4 References 256
Chapter 7: Engineering Interpretation of Charpy Impact Test
7.1 Introduction
7.2 Physical aspects of the Charpy test
7.3 Sub-sized and miniature specimens
7.4 Description of Charpy transition curves
7.5 Instrumented impact testing
7.6 References
Chapter 8: Indirect Fracture Toughness Estimation
8.1 General
8.2 Relation
between different transition temperatures
8.3 Fracture toughness correlations
8.4 References
Chapter 9: Structural Integrity Assessment Procedures
9.1 General
9.2 Plasticity correlation
9.3 Definition of brittle fracture reference fracture toughness
9.4 Simple plastic collapse criterion
9.5 References
Chapter 10: Transferabiltity of Fracture Toughness to Structural Integrity Assessment
10.1 General
10.2 Parameter validity
10.3 Constraint
10.4 Description of real flaws
10.5 Residual stresses
10.6 Warm pre-stressing
10.7 References
Chapter 11: Statistical Methods in Fracture Toughness Estimation
11.1 General
11.2 Some distribution functions
11.3 Rank probability estimation
11.4 Maximum likelihood estimation
11.5 Significance of deterministic lower bound estimates
11.6 Statistical planning
11.7 References
Chapter 12: Examples
12.1 Introduction
12.2 Assessing the fracture toughness of a 18MND5 (A533B) steel
12.3 Assessment of the EURO curve material’s fracture toughness
12.4 Assessment of thermal shock experiments
12.5 Assessment of the Point Pleasant Bridge failure
12.6 Assessment of pressurised thermal shock experiments
12.7 References
Chapter 13: The Re-analysed EURO Fracture Toughness Data Set
REVIEW
Dr David Lidbury, Serco TAS
Defect assessments are conducted routinely in many industries to assess the integrity or fitness for purpose of components whose failure would have unacceptable consequences, in terms of safety and economics. An essential feature of any defect assessment is an evaluation of the stability of a known or postulated flaw, which involves a comparison of load and resistance. Thus, proximity to crack initiation or unstable crack growth is assessed by calculating the crack driving force and comparing it with the material fracture toughness. This presents a major difficulty which is only partially addressed by current fracture toughness test standards. While fracture mechanics procedures for calculating the crack driving are relatively well developed, the material fracture toughness appropriate to a particular assessment can be much more difficult to estimate. Often this is because only an indirect guide as to the correct value to use is available, e.g. via knowledge of a transition temperature or impact energy. Even if fracture toughness data are available, there is the complication that the mechanisms of ductile and brittle fracture are quite different and that they respond differently to parameters such as temperature, loading rate, structural size, and geometry and load configuration (constraint). Moreover, variations in fracture toughness values from heat to heat or batch to batch can be considerable, requiring different statistical considerations for brittle and ductile fracture. This is further compounded if fracture toughness has to be evaluated over a range of temperatures for which a transition from ductile to brittle behaviour is possible.