Memorial Tribute to Takeo Yokobori

The origins of ICF go back to the 1920’s and a famous paper on Fracture by Alan Griffiths in the Transactions of the UK Royal Society and presented at the International IUTAM Conference in 1924 in Delft, The Netherlands. Then there was the very important research of George Irwin on Linear Elastic Fracture Mechanics in steel in the 1940’s, plus - as the discipline developed - papers in various realms on the mechanics and micromechanisms of fracture under various conditions by T Yokobori [3,4], AH Cottrell, CF Tipper, PC Paris, JR Rice, JF Knott, R Goldstein and many others towards the International Conference on Fracture which became ICF1 in Sendai, Japan in 1965.

ICF now has Gold & Silver Medals honouring various legendary figures in our global society: Yokobori, Cottrell, Irwin, Paris, Tipper but the greatest of these medals is the ICF Yokobori Gold Medal whose most recent honoured recipients are Toshimitsu Yokobori ICF Secretary-General for many years with Emmanuel Gdoutos ICF14 Executive Chair and Senior ICF Vice-President at ICF14 in Rhodes Greece in June 2017. The history of this trajectory of ICF from Sendai to Rhodes and now on to Atlanta at ICF15 in June 2021 and beyond into this extraordinary 21stC of globalization is the basis of this admiring memorial tribute volume edited by the famous son Toshimitsu Yokobori - and in which I am delighted to provide my lifetime homage to a Hero of Japan and Fracture.

One can go back to the “ancients” in the East and the West, even the construction of the monoliths at Stonehenge in Ancient Britain, to the Pyramids in Ancient Egypt and certainly to the Ancient Greeks & to India, China, Japan in understanding the history of structural integrity work in first of all stone construction - and thereafter to Leonardo in Italy in metals for early machines and the First Industrial Revolution in Britain.

However a tipping point occurred in structural integrity/fracture research when steel ship construction moved from riveting to welding in the 1940’s with then the concomitant fracture problems in the “Liberty Ships” and the work of George Irwin in the USA building on the earlier work of Alan Griffiths in the UK. This resulted in two major strands of research: one based on solid mechanics (the “Macro” approach) led by such as Irwin, Orowan, Argon, McClintock, Paris in the USA and the other based on physical metallurgy (the “Micro” approach) led by such as Cottrell, Bilby, Petch in the UK.

At ICF0 in 1959 via MIT was explored the idea of uniting these approaches and after meetings in November 1961 at MIT via an invitation from Ben Averbach Takeo Yokobori agreed to organize a micro/macro unifying fracture conference in Sendai, Japan in 1965. This became ICF1.

A group from the UK led by Roy Nichols and Alan Cottrell was then asked to organize a second conference in Brighton, UK in 1969 and this became ICF2 at which ICF as a global society was established with Statutes, a Founding Council and with Takeo Yokobori as Founder-President. Since then ICF has become a multi-stranded society as fully outlined in the parallel IJSFC “Taplin Festschrift” volume following my retirement as CEO/Treasurer 1985–2017. We have as a strong and friendly team supported globally by the thousands in the ICF world community assembled a series of fundamental Quadrennial Conference proceedings since 1969 as well as many ground-breaking [2] Interquadrennial Conference proceedings since 1983 in Beijing China (latterly via the work of Mimoun ElBoujdaini) - all of which immense body of work is indeed a tribute to the enduring legacy of Takeo Yokobori. Essentially all these archival research records are freely available on ICFweb.org via the work of the Italian Group on Fracture (Alberto Carpinteri and Francesco Iacoviello) and in the Yokobori Sendai Archives - a fount of knowledge for generations ahead.

A “New Era” of ICF now begins with ICF15 in Atlanta 2021 via the ICF15 Executive Chair Ashok Saxena and ICF16 in Melbourne 2025 via the ICF16 Executive Chair Raj Das looking towards iCF17 in Europe/Africa in 2029 which will be decided upon at ICF Council in Atlanta presided over by the new ICF President 2017–2021 Robert McMeeking.

I am delighted to have led - originally from Waterloo Canada - 1969–2017 a Canadian contribution to ICF over the complete history of ICF since foundation in Brighton - continuously on ICF Council throughout these decades. Since ICF4 Canada under the now Chairmanship of Bill Tyson has organized regular ICF-inspired Canadian Fracture Conferences via CFRC and he two Canadian Quadrennials in Waterloo in 1977 and in Ottawa in 2009 stand now I believe as beacons of creative innovation and excellence in the annals of ICF. All my own work in ICF has been inspired over this half century by Alan Cottrell (honoured [1] in another IJSFC volume) and above all by Takeo Yokobori .

ALL HAIL!