Warner Tjardus Koiter was born in
Amsterdam. After primary and secondary education, he enrolled into Delft University of Technology in 1931, graduating with honours as a
mechanical engineer in 1936. After graduation, he worked at the Dutch National Aeronautical Research Institute (NLL) in Amsterdam to work on airworthiness checking of aircraft structures. In 1938, he moved to the Government Patent Office and in 1939, he joined the Government Civil Aviation Office. During the war, he worked at NLL on subjects of his own choice. These investigations led to his
PhD thesis,
On the Stability of Elastic Equilibrium, which was defended in Delft, November 1945; it was supervised by
C. B. Biezeno. The thesis was written in Dutch, since the occupying forces only allowed theses to be written in either German or Dutch. As a consequence, its contents became only known to the broad scientific community after an English translation was edited by
NASA 15 years later. (Translation by Eduard Riks) In 1949, he was appointed Professor of Applied Mechanics in
Delft, where he stayed until his retirement in 1979. ==Achievements==