Georg Duffing

Georg Wilhelm Christian Caspar Duffing (born April 11, 1861 in Waldshut , † April 5, 1944 in Schwedt / Oder ) was a German engineer and inventor . In 1918 he described vibrations and their resonances with mathematical equations, the Duffing oscillator .

Family and career

Georg Duffing was born in Waldshut, Baden, in 1861 as the eldest son of the businessman Christian Duffing and his wife Julie Spies. In 1862 the family moved to Mannheim , where the father-in-law owned a carpentry shop. At high school, Duffing showed a special talent in mathematics and music. Due to a heart defect, Duffing renounced his initially intended military career and gradually enrolled at the Polytechnic in Karlsruhe from 1878 to 1883 in mathematics, engineering and mechanical engineering. Despite his heart defect, he won the Baden gymnastics championships. After completing his studies, although an exam might not have been taken, Duffing joined Cologne Deutz AG and worked on the development of a gas engine, which was successfully presented in 1905. In 1910, Duffing was an intern at Westinghouse Electric , a company that was a leader in power transmission. After returning to Germany in 1913, Duffing settled in Berlin as an inventor and freelance vibration scientist. Duffing attended Max Planck's lectures on quantum physics and carried out research with the support of Eugen Meyer at the Technical University of Berlin-Charlottenburg . In 1918 he published his widely acclaimed work on pendulum oscillations with a differential equation, which was named after him Duffing's differential equation or Duffing oscillator. In 1921, Duffing, who was in financial difficulties in Hamburg, joined the Stern-Sonneborn AG (Ossag) oil works , where he dealt with the friction behavior and viscosity of lubricating oils and headed the company's development laboratory. Due to an oil-related accident at Cap Arcona in 1929, Duffing, who had to fight for his reputation in court as a result of internal machinations in the company, got into a professional situation. In 1931 Duffing moved back to Berlin. Because of the air raids on Berlin, he took himself to safety in Schwedt, where he died on April 5, 1944. Georg Duffing was buried in Berlin in the cemetery of the Jerusalem and New Church Congregation. Duffing held various technical patents in Germany and the USA.

meaning

The value of Georg Duffing's equation for vibration theory lies to this day in its model character for physical systems and its suitability as a mathematical model for new approaches. It has been popular in chaos research since the 1970s , as it can exemplify the chaotic behavior of an initially ordered system.

Publications

• Contribution to determining the change in shape of cranked crankshafts , Springer, Berlin, 1906.
• Forced vibrations with a variable natural frequency , F. Vieweg, Braunschweig, 41/42, 1918.
• Friction test on the plain bearing, Association of German Engineers -Zeitschrift , 72 (15), 495-499, 1928.
• Elasticity and friction in belt drives , research in the field of engineering, 2 (3), 99-104, 1931.
• Measurement of toughness by uniform coaxial movement of a ball in a circular cylinder , Zeitschrift für Angewandte Mathematik und Mechanik, 13, 366-373, 1933.
• A new form of absolute viscometer , First World Petroleum Congress (London, UK), July 18-24, 1933.

literature

• FPJ Rimrott: Georg Duffing (1861–1944), Technical Mechanics , Volume 14, Issue 1, 1994 ( PDF )
• Ivana Kovacic, Michael J. Brennan: The Duffing Equation: Nonlinear Oscillators and Their Behavior , John Wiley & Sons, 2011, 386 pp. [1]

Individual evidence

1. ↑ Ivana Kovacic, Michael J. Brennan: The Duffing Equation: Nonlinear Oscillators and Their Behavior, John Wiley & Sons, 2011, p. 1

Web links

• Georg Duffing on Atomosyd.net
• Duffing oscillator at Scholarpedia