Daniel Drucker

Daniel C. Drucker studied at Columbia University, where he became interested in the conception, design and analysis of bridges. However, Raymond D. Mindlin suggested he write his dissertation on the subject of photoelasticity, which he completed in 1940. Afterwards, he lectured at Cornell University until 1943. Following military service, he worked for a short time at the Illinois Institute of Technology before transferring to Brown University, where he worked as a teacher and researcher from 1947 to 1967. It was at this university that William Prager founded the world-famous school of applied mathematics and mechanics in the 1940s and it was at this university that Drucker carried out his pioneering work on plastic theory. For example, based on the energy criterion for the stability of the elastic equilibrium (see section 10.4.5.1), he introduced the concept of material stability [Drucker, 1951], which today in the form of Drucker’s stability postulate enjoys an established place in the literature. Material stability – especially the stability of the infinitesimal dimensions – is crucial for dealing with the shake-down of loadbearing structures (Bleich-Melan shake-down principle) and the formulation of the stress-strain relationships in plastic theory. Drucker became dean of the faculty of engineering at the University of Urbana-Champaign in 1968. From 1984 until his retirement in 1994, he worked as a graduate research professor at the University of Florida, and he was editor of the Journal of Applied Mechanics for 12 years. Drucker’s work has been honoured with numerous awards, e. g. Lehigh, Brown, Northwestern and Urbana-Champaign universities plus the Haifa Technicon have all awarded him honorary doctorates, and the American Society of Mechanical Engineers (ASME) inaugurated its Daniel C. Drucker Medal in 1997. Charles E. Taylor wrote the following memorable words about Daniel C. Drucker:"In all of the thousands of hours we spent together, I never heard him utter a single swear word. He had a great sense of humor, but he never told a joke and he never spread gossip. I have never met a more honest man or pure person. Dan Drucker was the kind of person that we all try to be” [Taylor, 2003, p. 159].

Main contributions to structural analysis:

A more fundamental approach to stress-strain relations [1951]; Coulombs friction, plasticity and limit loads [1953]; On uniqueness in the theory of plasticity [1956]; A definition of stable inelastic material [1959]; On Structural Concrete and the Theorems of Limit Analysis [1961] 

Source: Kurrer, Karl-Eugen The History of the Theory of Structures, Wilhelm Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH, Berlin (Deutschland), ISBN 3-433-01838-3, 2008; p. 726