Hand-in date:  Thursday 11 January by 14:00

Assessment in this module has two components:

1. Coursework which is worth 50% of the overall marks.

2. A class test which is worth 50% of the overall marks.

The class test will be based around numerical questions similar to those given in the fracture mechanics tutorial ,and will cover simple applications of linear elastic fracture mechanics to fast fracture and sub-critical crack growth by fatigue or SCC mechanisms.  It will include cycle counting techniques, e.g. rainflow counting and reservoir counting.  The interactive resources associated with this module can be accessed from the following hyperlink http://www.tech.plym.ac.uk/sme/Interactive_Failure/intro.htm.

The laboratory sessions are intended primarily to act as opportunities to work through the interactive web-based resources associated with this module and to obtain experience, as appropriate for individual circumstances, of mechanical property testing (impact, tensile, fatigue), residual stress measurement by hole drilling, metallographic preparation and introductory metallurgy, and fractography.  Appropriate laboratory experience will be discussed with students individually.

The purpose of these case studies is described below in the section dealing with internet resources for this module.  The course work requires you to work through the case studies and the associated fractography resource, and some time will be allocated in the laboratory to initiate this process.  There is also a steel metallurgy training course by Corus available on CD-ROM on 2 computers in Smeaton Room 1.  This can be worked through individually and, together with the failure analysis case studies and fractography resource provides the necessary information to work through the failures assigned to the groups. 

The coursework will comprise an in-depth investigation and report on the implementation of a fracture control plan in an industrial sector, such as bridges, pipelines, welded structures etc.  This will be discussed in class and further guidelines posted on the student portal as the module progresses.  Additionally, I will meet with groups on a individual basis every  weeks in my office at the following times which have been arranged:

Group 1  13:00 - 13:30 on Thursdays            Group 2  16:00 - 16:30 on Thursdays

Group 3  15:00 - 15:30 on Fridays            Group 4  15:00 - 15:30 on Mondays

Group 5  14:00 - 14:30 on Fridays            Group 6  16:30 - 17:00 on Thursdays

Group 7  14:30 - 15:00 on Fridays

Coursework will be marked against two components; firstly a final PowerPoint presentation giving an outline of the application of fracture control in the chosen industry, including historical development, classic failures that motivated development of fracture control plans and details of the parts of the fracture control plan.  The precise format will be discussed during classes.  Secondly, a written report will add detail around a specific example of application of a fracture control plan and show, step by step, how the plan would be implemented with illustrative calculations etc.  The report should be around 2000 to 3000 words in length with appendices giving illustrative calculations etc.

INTERNET RESOURCES

The internet resources provided for this module are extensive and structured to support progressive individual learning.  They comprise several sets of web pages, some of which have interactive content.

1.         A full set of tutorial problems dealing with the application of elastic fracture mechanics, from Griffiths equation, through to application of the stress intensity factor to fracture, fatigue and SCC are accessible on the internet at:

http://www.tech.plym.ac.uk/sme/Tutorials/FMTut/intro.htm

These problems are aimed at developing your ability to interpret the analytical requirements of realistic cases, and are carefully structured to lead you progressively through a range of fracture mechanics applications.  As a result of a number of years experience with problems that students face in this area, there are online hints which lead you to the area of likely difficulty in the questions.  Full solutions are also given but, be warned - looking at the solutions without having attempted the questions will not imprint the solution techniques in your mind, and you will struggle in the examination.  The purpose of the internet presentation is to optimise time usage and avoid lengthy delays arising from interpretive difficulties, as the problems are not intrinsically tricky.  Relevant theory cards are also available online, as is a scientific calculator and graphing activity.  Links to some other relevant sites are also included.

If you work through all the problems in the tutorial, the examination questions should pose no problem.

2.         An extensive discussion of engineering failures, illustrated through a case study approach, is available online at:

http://www.tech.plym.ac.uk/sme/FailureCases/FAILURE.htm

This document deals with failures arising from all parts of the design process, e.g. management and marketing failures, as well as failure due to cracking problems.  Examples include the Tacoma Narrows bridge, the Comet airliner, the Challenger Space Shuttle, Chernobyl, the Spruce Goose aeroplane, the DeLorean car and the Sinclair C5 electric vehicle.  It draws out the technological and other consequences of failures.

3.            Interactive case studies in forensic engineering can be found at:

http://www.tech.plym.ac.uk/sme/Interactive_Failure/intro.htm

These aim at illustrating a number of applications of some techniques that are widely used in industrial failure analysis, e.g. metallography, fractography and simple fracture mechanics.  The examples are chosen and presented so as to guide the learner through the analytical steps and thought processes used in solving such problems.  The learning interface involves aspects like:

·        Focussed and hyperlinked background theory and information regarding use of techniques together with interpretation of information.

·        Multi-choice intermediate step in the analyses.

·        Opportunities for the learner to explore other decisions in the analysis tree, and their possible consequences

These particular examples are chosen to illustrate unusual, interesting or potentially misleading aspects of failure investigation, often in the context of the impact of engineering decisions on litigation, insurance claims, assessment of responsibility, and design/manufacturing modifications.

BOOKS

Fracture Mechanics 

There are a number of excellent books available on the theory and applications of fracture mechanics, some of which are given below together with a brief description of their strengths.  The library contains a number of these books and, particularly, the complete set (Vols. 1-20) of the ASM Handbooks.

1.         HL Ewalds and RJH Wanhill, Fracture Mechanics, 1984 Arnold, London.  This is an excellent text which gives a clear exposition of basic theory, elastic limitations and toughness testing methods.  A strong point in the book is the linking of metallurgical aspects with mechanical behaviour.  

2.         AP Parker, The Mechanics of Fracture and Fatigue: An Introduction, 1981, E&F Spon, London.  This book covers the theoretical background to the subject rather well, detailing the mathematics in a clear way and leads into the application of FM to service situations.  

3.         ST Rolfe and JM Barsom, Fracture and Fatigue Control in Structures: Applications of Fracture Mechanics, 1977, Prentice-Hall, New Jersey.  As its title implies, this book is firmly related to industrial applications of fracture mechanics and is a useful reference for a practising engineer.  

4.         D Broek, The Practical Use of Fracture Mechanics, 1989, Kluwer Academic Publishers, London.  This is another excellent practical text, which draws on the authors experience of  teaching fracture mechanics to practising engineers.  Mathematics is presented in a way that appeals to intuition and insight, rather than as formal derivations.  

5.         ASM Handbook, 10^th edition, Volume 19 - Fatigue and Fracture, ASM International, Materials Park, Ohio.  A very comprehensive guide, as befits a publication of ASM International.  

6.         Journals such as Engineering Fracture Mechanics, Fatigue and Fracture of Engineering Materials and Structures, International Journal of Pressure Vessels and Pipelines, International Journal of Fracture all contain useful articles, although seldom of an introductory nature.  

7.         ASM Handbook, 10^th edition, Volume 11 - Failure Analysis and Prevention, ASM International, Materials Park, Ohio.  A very comprehensive guide, as befits a publication of ASM International.  

8.         ASM Handbook, 10^th edition, Volume 12 - Fractography, ASM International, Materials Park, Ohio.  A very comprehensive guide, as befits a publication of ASM International.

Fatigue Design and Crack Growth 

1.         RW Hertzberg, Deformation and Fracture Mechanics of Engineering Materials 3^rd edition, 1989, Wiley, New York.              A good  introductory text to deformation mechanisms, fatigue and fracture mechanics in both metals and nonmetals.

2.         NE Dowling, Mechanical Behaviour of Materials, 1993, Prentice-Hall, New Jersey.  A comprehensive undergraduate or postgraduate textbook that deals with fatigue under multiaxial loading, as well as the more usual topics.  Emphasis is placed on analytical and predictive methods and many worked examples are given. 

3.         JE Bannantine, JJ Comer and JL Handrock, Fundamentals of Fatigue Analysis, 1990, Prentice-Hall, New Jersey.  This covers stress-life, strain-life and fracture mechanics approaches to fatigue lifing in some detail.  

4.         A Buch, Fatigue Strength Calculation, 1988, Trans Tech Publications, Switzerland.  This is a book for practising engineers who deal with fatigue design on a daily basis.  It is very competent and thorough, with many worked examples.   

5.          Society of Automotive Engineers, Fatigue Design Handbook AE-10 2^nd edition, 1988, SAE, Warrendale PA.  A design guide for practising engineers, which includes a lot of fatigue data for common metals used in the vehicle industry.   

6.         S Suresh, Fatigue of Materials, 1991, Cambridge University Press.  An excellent book which goes into the subject of fatigue in detail.  It is suitable for postgraduate and research students, but is also accessible by undergraduates with an interest in the topic.  

7.         Metals Handbook, 9^th edition, Volume 12 - Fractography, 1987, American Society for Materials, Materials Park, Ohio.  Very good encyclopaedia of fractographs and techniques for studying fractography.  

8.         Various journals are available, most of which publish occasional review papers dealing with aspects of fatigue, e.g. International Journal of Fatigue, Fatigue and Fracture of Engineering Materials and Structures.