As Cottrell pointed out in his opening address at ICF2, everyone is concerned, from a very early age, with why things break. Children's toys break, we break our bones, the engines of our motor cars and washing machines fracture - but more importantly, advanced large-scale structures can fracture - pipelines, bridges, skyscrapers, nuclear reactors, ships and aircraft - even the very earth itself fractures in earthquakes. The understanding and alleviation of all such fractures are the special concern of the scientists and engineers who gather together every four years at each International Conference on Fracture. The inspiration of these conferences has been Professor Takeo Yokobori, Founder-President of ICF. It is the principal purpose of ICF to regularly bring together, from every corner of the world, the major workers in all aspects of fracture for a re-assessment of the advances made and to provide a basis for sound and relevant scientific and engineering work in the future. This purpose will surely be achieved at 1CF4. But, in Canada, in preparing for 1CF4, we were especially conscious of the larger purpose of placing all this research in the full context of society as a whole. As the complexity of our technological systems increases, so do the possible catastrophic consequences of failure. By way of emphasis, one may cite the Presidential Campaign of 1976 in the United States where the consequences of fractures in nuclear reactors, and hence their safety, played a. significant role. The safety of many of our energy systems including reactors, offshore structures, super-tankers, LNG ships, pipelines, is now of very wide social concern and is discussed regularly and thoroughly in the ordinary press. Accordingly, it is both an obligation and extremely prudent that we, at this conference, address ourselves to our responsibilities to the safety of the technological world at large.
Thus, the dominant themes of ICF4 are the applied aspects of fracture and especially the application to large-scale engineering structures. At the same time, the broad purpose of bringing together workers in every aspect of fracture has not been forgotten. But, to ensure that the social implications of our work can be fully appreciated and discussed, two Plenary Panel Discussions have been organized under the general heading Fracture and Society.
The International Congress on Fracture (ICF) was created through the vision of Takeo Yokobori in Sendai, Japan in 1965. The primary emphasis of Yokobori was to join the micro- and macro-mechanics aspects of fracture research. The outstanding growth of ICF demonstrates that the founding effort was the right approach to the right topic at the right time. The "ICF Brand" is now recognised around the world as one of the leading international societies in the broad field of structural integrity, fracture, fatigue, creep, corrosion and reliability - from biological to geophysical materials, from nano to macro scales, from basic science to practical engineering & technology and systems modelling. In this paper we trace the history of the development of fracture research and of ICF via the many threads of, for example, the E24/E9 committees of ASTM; the US Committee on Ship Steel linked to work on the Liberty Ships in the Engineering Laboratories, Cambridge, England; early work in Germany, France & Japan - culminating in the MIT Swampscott Fracture Conference of 1959 ("ICF0"), the pre-cursor to ICF1 in Sendai in 1965. We then examine the impact of the ICF quadrennial series of international fracture conferences from ICF1 through to ICF12 in Ottawa, Canada in 2009. The key is the original research presented in some 5000 scientific papers and to be made available online on the new ICF website (www.icf-wasi.org). Finally we examine the evolution of ICF since 2009 towards ICF13 in Beijing, China in 2013 (www.ICF13.org) and forward for the next decade and beyond.
In 1957 George Irwin told his wife Georgia that it was time for him, as his task ahead, to “spread the message of Fracture Mechanics”. Indeed he began an effective effort to do so. He named the approach “Fracture Mechanics” at that time. In 1958 he presented his methods at the Naval Symposium on Structural Mechanics held at Stanford University, and it was well received. His methods were also well received in other Mechanics circles.
In the late 1950s test firings of the Polaris submarine launched missile resulted in 20 failures of the steel engine case out of 40 test firings. This missile was a major planned US deterrent in the “cold war” situation at that time. These failures were traced to flaws in the welds in the assembly of the engine case. As a consequence the Department of Defense asked ASTM to form a Special Committee to attempt to resolve this problem. The Special Committee at that time did not have the designation as the E-24 committee. That came later.
Professor Jack Low of Carnegie-Mellon University was designated as the committee chairman, and the membership included George Irwin of the Naval Research Laboratory, William Brown and John Srawley of NASA Lewis Laboratory, Charles Tiffany who at Boeing developed the proof test logic for space vehicle pressure vessels, and others. They explored flaw detection techniques and reliable inspection facilities to assure safety of these vessels.
Their activities continued over several years to ensure that the techniques developed were the best for the principle problem that they had resolved. Meanwhile, their meetings occurred several times each year for a day, and then subsequently expanded to a
Also in the early 1960s Syracuse University held a conference at the Sagamore conference center in which many of the presentations discussed fracture and fatigue progress using the Fracture Mechanics approach. Professor Volker Weiss organized the meeting with the sponsorship of the army. Further, in 1964 ASTM held a conference on progress in Fracture Mechanics during their annual national meeting in Chicago. William Brown of NASA Lewis Center organized the meeting so as to cover the overall field as developed at that time. The ASTM Special Technical Publication, STP 381, was a book resulting from that conference, released in 1965, which represented the rapid progress in the field at that time. It was the best-selling book of ASTM! We had all worked very hard on technical papers to cover the part of the field we were assigned to discuss.
The paper, which is a somewhat up-dated version of the author’s 1999 Royal Society/Royal Academy of Engineering Lecture of the same title, presents an overview of the issues involved in the initial design of structures and machines, in material selection and guarantees of quality, in erection and fabrication, in non-destructive examination and through-life “health-monitoring”, and in assessment of the threats to integrity posed by the presence of defects. Attention is drawn to the R6 Failure Assessment Diagram and to the characterisation of fatigue-crack growth. Finally, the issues are set in terms of a risk-based probabilistic approach to the occurrence of failure and to the consequences of such failure. The 1999 Lecture was given to an audience having a non-specialist, general science/engineering background and so was put in more popular form than would be the norm for a specialist audience. This form has been retained in the present paper, but it is hoped that no “integrity of message” has been lost by so doing.
The paper's title relates to the difference in emphasis placed on ensuring the integrity of a structure, contrasted with that relating to the durability of a machine. The former is usually treated as a "one-off" assessment: the latter is more involved with calculating the lifetime and specifying appropriate inspection periods. Integrity assessments do, of course, take account of changes with time and this is illustrated in the paper by considering the temporal variation of the assessment point on a Failure Assessment Diagram (FAD) and the factors affecting the movement in its position: both crack growth and changes in material properties. Probabilistic effects are also treated. Durability issues are addressed by detailed consideration of the "lifing" of a turbine disc in a gas turbine, demonstrating the importance of initial defect size and its control. These principles are generally applicable to a wide range of other machine components.
University of Bochum and Hamburg University of Technology, Germany
Antony Ingraffea, Cornell University, Ithaca, NY, USA
Daniel Lovegrove, Elsevier, Oxford, UK
The existence of books and articles and rules for good behaviour – in particular when they are excavated from geological layers going far back in history - may create the impression that in prior times people knew how to behave themselves, that obviously they had good manners. However, the opposite is true. When people talk about ethics, good behaviour, what to do and what not to do, then you know that there is something wrong. This is also true in the sphere of science where the public tends to believe that only distinguished persons ranking high in ethics reside. Science publication media are increasingly confronted with problematic paper submissions. This is not only related to authors, not even related only to publication as such, the problem is much wider as we will see later. This article is based on our own experience in editing and publishing a journal; however, we also use material provided to us by responses to our earlier presentation at ICM11 in 2011.