Christian Otto Mohr

Christian Otto Mohr, cited mostly as Otto Mohr ( born October 8, 1835 in Wesselburen (Holstein ); † October 2, 1918 in Dresden) was a German engineer and structural engineer.

Life and work

Otto Mohr worked prior to his career as an engineer in 1850 as parish clerk in Wesselburen. A year later he began at the age of 16 years, his studies in engineering at the Polytechnic Institute in Hannover. His teachers included the students Schubert, Moritz Rühlmann. In 1855 he was assistant engineer and later engineering and building officer at the Royal Hanoverian State Railways ( HSEB ) in Lüneburg. In 1860 he published as an assistant in the service of HSEB a work on the continuous bending beam. This allowed for a reliable design of continuous beams, wrought in the professional world attention.

On November 18, 1852 he founded, together with Joachim August Danielsen and Max Stegemann the country team Slesvico - Holsatia from which the still existing Corps Slesvico - Holsatia emerged.

Following his tenure at the HSEB he was involved in the construction of the Grand Duchy of Oldenburg State Railways. During this time, Mohr designed one of the first steel bridges in Germany with clear triangle truss trained and developed a simple method of calculation which was perfected in 1863 by August Ritter and since then as Ritter's cutting method (or knight - section method ) is known.

1867 Mohr's scientific achievements were already in such demand that he was appointed to the Polytechnic Institute in Stuttgart ( predecessor of the University of Stuttgart), where he henceforth became Professor of Applied Mechanics, tracing and earthworks. He could the theoretical substance of mechanics in an easily understandable form offer up so that his lectures were very well attended and later even released in autographierter form. In science, he reported a significant simplification, as a graphical method (also: Mohr's analogy ) developed for the determination of the bending line as a catenary curve, which until then was only mathematically possible by double integration.

Most famous remains Mohr posterity but by the developed by him, simple method, principal stresses of plane stress with the help of named after him Mohr's circle derive graphically from the shear and normal stresses, or the plane stress variables between local Cartesian coordinate systems to transform. The method is applicable in an analogous manner of elongation, the same is true for the Mohr's circle of inertia.

1873 Mohr received a professorship at the Polytechnic Dresden. In 1869, resulting Chair of road, water and railway construction was unoccupied because the previous owner Claus Koepcke accepted an appointment as supreme chief of all the construction of railways in Saxony's Ministry of Finance. At his inauguration he was entrusted with the adoption of courses William Frankel to Graphostatik. Only three years later, his remit extended from 1876 still around the trade strength of materials. Mohr was also a colleague of Ludwig Burmester, inventor of the eponymous Burmester templates. Between 1874 and 1875, Mohr published a truss theory he had developed on the basis of the general labor movement and the external virtual work.

1894 was a change from the Engineering Department at the General Department, where he took over as successor Gustav Zeuners the Department of Engineering Mechanics and Strength of Materials. In this office he stayed for six years until he in 1900 at the age of 65 years laid down the direction of the Chair.

Mohr worked 33 years as an academic teacher, of which 27 years in Dresden. There he bought the villa in 1877 Leubnitzer Str 7 ( 1890 Villa Haniel ) where he lived until 1884. He spent his retirement on his estate in Wachwitz in Dresden, still connected to the scientific work. On October 2, 1918, six days before his 83rd birthday, died Otto Mohr. His resting place is located on the St. John's Cemetery in Dresden- Tolkewitz.

Writings

  • Treatises in the field of engineering mechanics, Ernst and Son, 2nd edition 1914
  • What circumstances cause the elastic limit and the breaking of a material? . In: journal of the Association of German Engineers. No. 24, 1900, pp. 1524-1530 and 1572-1577.
  • Contributions to the theory of wood and iron structures. In: Journal of Architectural and Engineering Association to Hannover 14 (1868 ), Sp 20-52, 397-400. Schmorl & von Seefeld, Hannover 1868 ( digitized and full text in German Text Archive )
  • Contributions to the theory of earth pressure, Journal of Architectural and Engineering Association Hanover, Volume 17, 1871, p 344, Vol 18, 1872, pp. 67, 245
  • Contribution to the theory of the framework. Schmorl & von Seefeld, Hannover 1874/75 1 T. In: Journal of Architectural and Engineering Association in Hannover (1874 ), 509-526 Sp. Schmorl & von Seefeld, Hannover 1874 ( digitized and full text in German Text Archive )
  • Continuation. 2 T. In: Journal of Architectural and Engineering Association in Hannover (1875 ), 17-38 Sp. Schmorl & von Seefeld, Hannover 1875 ( digitized and full text in German Text Archive )

Awards

186544
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