Paul Mansour Naghdi (March 29, 1924 – July 9, 1994) was a professor of mechanical engineering at University of California, Berkeley.
In 1951 got a PhD at the University of Michigan with the dissertation: "Large Deformation of Elasto-Plastic Circular Plates with Polar Symmetrical Loading".
[1] During the period 1949 to 1951, he held the position of instructor in engineering mechanics, and upon receipt of the Ph.D., he was appointed assistant professor at Ann Arbor.
From 1991 onwards, he held the Roscoe and Elizabeth Hughes Chair in Mechanical Engineering, and in 1994 he was advanced to the newly instituted position of professor in the graduate school.
A consummate theoretician, he was most strongly attracted by fundamental questions in mechanics, and always sought to treat these at the highest level of generality.
Working along classical lines, Naghdi subsequently developed a systematic treatment of elastic shells and plates undergoing small deformations, which was published in 1963.
Naghdi embraced the emerging theoretical developments and began to consider in a new light the mechanics that he had learned from classical authors such as Love, Lame, and Whittaker.
As Naghdi came to realize in the late 1970s, sheets of water admit the same kinematical treatment as solid shells, but differ in respect to constitutive properties.
Naghdi and his co-authors developed an elegant theory of fluid surfaces and applied it successfully to a wide variety of problems, including waves on a stream of variable depth, flow past obstacles and boats in lakes.
In the early 1960s, Naghdi set himself the task of extending plasticity theory to encompass elastic-plastic materials at finite deformations.
After his long career for over three decades as a professor in the Department of Mechanical Engineering, he succumbed to lung cancer at his home in Berkeley, California.
For his fundamental contributions to plasticity and to shell theory, he was awarded the Timoshenko Medal by the ASME in 1980, which justly placed his name on the list of the top engineering scientists of this century.