George Rankine Irwin

George Rankin Irwin , (February 26, 1907 – October 9, 1998) was an American scientist in the field of fracture mechanics and strength of materials. He is known for defining the stress intensity factor, , which is used to characterise the state of stress around a crack tip. When this value exceeds the fracture toughness of a material the crack will rapidly propagate.

He was involved in the development of several standards and led several committees for the American Society for Testing and Materials (ASTM).

In 1967, Irwin was recruited to Lehigh University as the Boeing University Professor by long-time collaborator Paul C. Paris, the father of modern methods for predicting crack growth and its control in aircraft structures. Irwin served for five years before reaching mandatory retirement age. In his tenure, he continued his collaboration with Paris, and collaborated with, influenced, or assisted many notable individuals in the fracture mechanics community, including: F. Erdogan on cracks in thin-walled shell structures; A. A. Wells of the British Welding Institute on characterizing fracture in normally ductile steel structures; F. A. McClintock, Massachusetts Institute of Technology and John W. Hutchinson, Harvard University, on the development of fracture mechanics procedures in the presence of substantial ductility; James R. Rice, Harvard University, on developing the J integral approach for characterizing the onset of crack growth in ductile materials; L. B. Freund, Brown University, and M. F. Kanninen, Southwest Research Institute, on the dynamics of inertial limited crack propagation and arrest.

In 1972, Irwin joined the faculty of the University of Maryland, College Park where he worked in the field of dynamic fracture, specifically concerned with crack arrest and the implications in a loss-of-coolant accident in a nuclear power plant. He contributed to The Stress Analysis of Cracks Handbook.

Memberships and honours Irwin was a member of the America National Academy of Engineering and a Foreign Member of the Royal Society of London. 1967 - Fellow, ASTM 1969 - University of Illinois Engineering Achievement Award 1969 - U. S. Navy Conrad Award 1969 - Alumni Achievement Award, University of Illinois 1973 - SESA Murray Lectureship Award 1974 - Lehigh University Academic Leadership Award 1974 - ASTM honorary member 1974 - American Society for Metals Sauveur Award 1976 - The Grande Medaille Award of the French Metallurgical Society of France 1977 - ASME Nadai Award 1977 - B. J. Lazan Award from the Society for Experimental Mechanics 1977 - Honorary degree, doctor of engineering, Lehigh University 1977 - Election to the National Academy of Engineering 1978 - ASTM-Irwin Award 1979 - Francis J. Clamer Clauier Medal of the Franklin Institute 1982 - Governor's Citation for Distinguished Service to Maryland 1982 - Tetmajer Award of the Technical University of Vienna, Austria 1985 - Fellow, Society for Experimental Mechanics 1986 - ASME Timoshenko Medal 1987 - ASM Gold Medal for Outstanding Contributions to Engineering and Science 1987 - Elected to foreign membership, British Royal Society 1988 - ASTM Fracture Mechanics Award and the George R. Irwin Medal 1989 - Honorary membership in Deutscher Verband für Material Prufung 1990 - Honorary membership in the American Ceramic Society 1990 - Albert Sauveur Lecture Award 1992 - George R. Irwin Research Award, University of Maryland 1993 - Engineering Innovation Hall of Fame at the University of Maryland 1998 - A. James Clark Outstanding Commitment Award University of Maryland 1998 - Appointed Glenn L. Martin Institute Professor of Engineering