Friedrich Bleich

Friedrich Bleich studied civil engineering at Vienna TH (1896–1902); from 1902 to 1906 he was employed in the Prag-Bubno bridgebuilding company and afterwards as a senior engineer at Waagner-Biro A.G. in Vienna until he founded his own consultancy in 1910. In that same year he became co-founder of the journal Der Eisenbau, the scientific orientation of which occupied him extensively until publication was discontinued during the period of runaway inflation. Over the years 1914–16 he deputised as lecturer for bridge-building at Vienna TH. He gained his doctorate in 1917 with his thesis Der Viermomentensatz und seine Anwendung auf die Berechnung statisch unbestimmter Tragwerke supervised by Friedrich Hartmann and Anton Zschetzsche. He acted as an outstandingly successful scientific secretary to the International Association for Bridge & Structural Engineering (IABSE) from ist foundation in 1938. Hitler’s annexation of Austria and the rise of the Third Reich forced Bleich to flee to Zurich in 1938. He emigrated to the USA in 1941, where he was employed by Albert Kahn, Associated Architects & Engineers, in Detroit; later he was offered a post at the US Institute for Steelwork. From 1947 until his death Bleich worked for Frankland & Lienhard, a firm of consulting engineers in New York. He worked on bridge designs, carried out research into the cause of the collapse of the Tacoma Narrows Bridge and – on behalf of the US Navy Department – compiled information on buckling and warping stresses in metal components. He was the first structural engineer to employ the finite difference method for the analysis of continuous beams (1904) and together with Ernst Melan developed a generalisation of this method [Bleich & Melan, 1927]. He also made vital contributions to the development of the theory of stability for steel buildings during the consolidation period of structural theory; over that period, his theorem of four moments enjoyed great popularity among practising engineers. Bleich’s monograph [Bleich, 1924] on the theory and analysis of steel bridges gradually superseded Josef Melan’s bridge books from the late 1920s onwards. Bleich was an excellent representative of that group of consulting engineers who made contributions to practical design and construction but also the formation of structural theory during the consolidation period.

Main contributions to structural analysis:

• Die Berechnung statisch unbestimmter Tragwerke nach der Methode des Viermomentensatzes [1918];
• Theorie und Berechnung der eisernen Brücken [1924];
• Die gewöhnlichen und partiellen Differenzengleichungen der Baustatik [1927];
• Buckling Strength of Metal Structures [1952]

Source: Kurrer, Karl-Eugen The History of the Theory of Structures, Wilhelm Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH, Berlin (Deutschland), ISBN 3-433-01838-3, 2008; p. 717-718