William Prager
May 23, 1903 - March 16, 1980
|
Scientific Discipline: Applied Physical Sciences Membership Type:
Member
(elected 1968)
|
Early in his career, William Prager established a powerful reputation as a mathematician and an engineer. His fields of study were primarily the statics and dynamics of structures, the theories of elasticity and plasticity, numerical analysis, and nonnumerical applications of computers. After leaving Germany (his home country) because of his anti-Nazi beliefs, Prager joined a world famous group in applied mechanics and applied mathematics at Brown University. In 1946, he founded the Division of Applied Mathematics at the university, and he served as its first chairman. He guided the research and teaching of the division, surrounding himself with young individuals working in a variety of fields, such as applied mechanics and mathematics, physics, and engineering. During this period, Prager’s research focused on a broad range of topics, including the mechanics of continua of all types, problems of traffic flow, and application of computers to problems in economics and engineering. His later work in applied mechanics dealt with illuminating representations in function space, variational principles for stability, stress-strain relations in the plastic range, the theories of limit analysis and design, and several other studies of importance. One of his more significant findings was the Drucker-Prager yield criterion, which was a pressure dependent model that investigated the plastic deformation of soils to determine if they underwent plastic yielding.
Prager was educated in Darmstadt, Germany at the Institute of Technology, where he earned his degree in 1925 and his doctorate the following year. After lecturing at Darmstadt until 1929, Prager was appointed the acting director of the Institute of Applied Mechanics at the University of Göttingen; he held the position for four years. Upon the rise of Nazism, he left Germany to become a professor of theoretical mechanics at the University of Istanbul from 1933 to 1941. He then left for the United States to be a professor of applied mechanics at Brown University from 1941 to 1965. During this time, Prager was the founder, and managing editor, of the Quarterly of Applied Mathematics (1943-1965). He accepted the L. Herbert Ballou University Professorship in 1959, and in 1965, he left for an applied mechanics professorship at the University of California, San Diego where he remained until his retirement in 1973. Prager was a member of several scientific societies, including the American Mathematics Society, the American Society of Mechanical Engineers (ASME), and the Society for Industrial and Applied Mathematics. For his mathematical and engineering contributions, he received the Worcester Reed Warner Medal of ASME in 1957 and the Theodore von Kármán Award of ASCE in 1960.
