Jacob P. Den Hartog

Jacob Pieter Den Hartog , called Jaapie, (born July 23, 1901 in Ambarawa on Java , then Dutch East Indies; † March 17, 1989 ) was a Dutch-American engineer for mechanics. He was a professor at the Massachusetts Institute of Technology (MIT).

Life

Den Hartog first grew up in Java, where his father was a teacher. This was because of radical views - among other things, he was in the Dreyfuß affair on the side of its defenders - he was dismissed from school in Amsterdam.

He returned to the Netherlands in 1916, went to school in Amsterdam and studied electrical engineering at the TU Delft from 1919 , graduating in 1924. He then emigrated to the USA, where he worked as an electrical engineer at Westinghouse Electric and there under the influence of Stepan Tymoshenko came, who accepted him as an assistant and had a number of electrical and mechanical vibration problems dealt with. At the same time he attended evening mathematics classes at the University of Pittsburgh , where he received his doctorate in 1929. However, he had previously published a number of scientific papers that arose from the practical problems he was faced with at Westinghouse. When the laboratory was reorganized in 1930, he became head of the dynamics department. In 1931 he was during a sabbatical year a year in Göttingen in the laboratory of Ludwig Prandtl (whose employees Oskar Karl Gustav Tietjen was previously at Westinghouse and Den Hartog had translated its BASED on Prandtl lectures hydrodynamics textbook). In 1932 he became a professor of applied mechanics at Harvard University . During his time at Harvard he was involved in the organization of the International Congress of Applied Mechanics in Cambridge, Massachusetts in 1938 and taught regularly at the Summer Mechanics Academies organized by Stephen Timoshenko at the University of Michigan . During the Second World War he volunteered for the US Navy and served as an officer first in the Taylor Model Basin in Bethesda, Maryland and then in the Bureau of Ships in Washington DC, where he was busy with the treatment of vibration problems in shipbuilding. From 1943 he had the rank of Commander and 1945 Captain. In 1944/45 he was part of a technical commission that followed the advancing troops in England, France, Belgium, the Netherlands (he was in Amsterdam on Victory Day ), Denmark and Germany. From 1945 he was Professor (Mechanical Engineering) at MIT. In addition to his work as a university lecturer, he was also a much sought-after consulting engineer and gave summer courses on vibrations for industrial engineers. From 1954 to 1958 he headed the Mechanical Engineering department .

Den Hartog has been an expert on mechanical vibrations in the USA since the 1920s, about which he wrote a well-known textbook in 1934. The classic textbook came from the physicist John William Strutt, 3rd Baron Rayleigh , and the theory was little known among engineers at the time. In his book Mechanical Vibrations , Den Hartog dealt in particular with machine vibrations .

In 1972 he received the Tymoshenko Medal . He was a member of the National Academy of Sciences , the American Academy of Arts and Sciences (1934), the National Academy of Engineering and the Royal Netherlands Academy of Sciences . The MIT Department for Mechanical Engineering awards a Den Hartog Prize for outstanding teaching. In 1981, he received the James Watt International Medal and in 1982 the Japanese Order of the Rising Sun . He received the Trente-Crede Medal from the Acoustical Society of America . Den Hartog has received several honorary doctorates (Carnegie Institute of Technology, Salford University, TU Delft, Newcastle-upon-Tyne, Gent).

Stephen H. Crandall is one of his PhD students .

Since 1926 he was married to Elisabeth F. Stolker.

Fonts

• Mechanical Vibrations , McGraw Hill 1934, 1940, 1947, 1962
  • Mechanical vibrations , Springer Verlag 1952 (translated after the 3rd edition, a German translation of the first edition was published by Springer in 1936)
• Mechanics , McGraw Hill 1948, reprint Dover
• Strength of Materials , McGraw Hill 1949, Reprint Dover
• Advanced Strength of Materials , McGraw Hill 1952, Reprint Dover

literature

• Stephen H. Crandall , Obituary in Biographical Memoirs Members National Academy 1995