Jacob Pieter Den Hartog

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

Life

Den Hartog initially grew up in Java, where his father was a teacher (because of radical views - among other things he was in the Dreyfus affair on the part of its defenders - he was released in Amsterdam from the education service ).

He returned in 1916 to the Netherlands, went to Amsterdam to school and studied from 1919 at the Delft University of Technology Electrical Engineering, with completion in 1924. Afterwards he emigrated to the USA where he worked as an electrical engineer at Westinghouse Electric and there under the influence of Stepan Tymoshenko came, who took him as an assistant and let work on a range of electrical and mechanical vibration problems. At the same time he attended evening math courses at the University of Pittsburgh, where he received his doctorate in 1929. He previously published a number of scientific papers that emerged from the practical problems with which he was confronted at Westinghouse. In the reorganization of the laboratory 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 Tietjens was previously at Westinghouse and Den Hartog whose system based on Prandtl's lectures hydrodynamics textbook was translated). In 1932 he became 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, 1938 in Cambridge (Massachusetts ) and taught regularly in the summer academies of Mechanics, organized Stephen Timoshenko at the University of Michigan. During World War II he volunteered for the U.S. Navy and served as an officer in the Taylor Model Basin, first in Bethesda (Maryland ), and then in the Bureau of Ships in Washington DC, where he was engaged in the treatment of vibration problems in shipbuilding. From 1943, he held the rank of Commander in 1945 and a captain. 1944/45, he was part of a technical commission that in England, France, Belgium, the Netherlands ( he was on the Victory Day in Amsterdam ), Denmark and Germany followed the advancing troops. From 1945 he was Professor (Mechanical Engineering ) at MIT. In addition to his work as a university teacher, he was also a much sought-after consultant engineer and gave summer courses on vibrations for engineers from industry. 1954 to 1958 he headed the department of Mechanical Engineering.

Den Hartog was in the U.S. since the 1920s as an expert on mechanical vibrations, about which he wrote in 1934 a well-known textbook. The classic textbook originated by the physicist Lord Rayleigh and the theory was then little known among engineers. In his book Mechanical Vibrations Den Hartog went on a particular machine vibrations.

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

His PhD is one of Stephen H. Crandall.

Since 1926 he was married to Elizabeth F. Stolker ( whom he married on a holiday in Amsterdam).

Writings

• Mechanical Vibrations, McGraw Hill 1934, 1940, 1947, 1962 Mechanical vibration, Springer Verlag, 1952 ( translated from the third edition, it also appeared to have a German translation of the first edition in 1936 by Springer )