Ernst Chwalla

After completing his civil engineering studies at Vienna TH, Chwalla worked as assistant to the chair of bridge-building at the same establishment. He gained his doctorate in 1926 with a dissertation on the lateral rigidity problems of open bridges and completed his habilitation thesis in 1928 with a contribution to the theory of stability. Both these works, written in Vienna under the direction of Prof. Friedrich Hartmann, helped Chwalla to create the foundation for his pioneering work on the theory of stability. When he was just 28 years old he was offered the chair of structural mechanics at the German Technical University in Brno, a post that had been held before by Joseph Melan and Paul Neumann. Together with Jokisch, he succeeded in integrating the stability problem into the displacement method in 1941. In the same year Chwalla presented his introduction to the theory of structures, which by 1954 had reached its third edition; this work is characterised by systematic inclusion of the higher sciences of strengths and mechanics of materials. During the 1940s he had a decisive influence on the drafts for German stability standards in structural steelwork (DIN 4114). At the end of the war Chwalla was taken prisoner by the Russians and sent to a Czech work camp. With the help of Czech professors, who were aware of his fate, a police investigation was initiated that finally led to his release from the camp in June 1945. From there he went on to set up a new career for himself in Vienna, with the help of Karl Girkmann and others. In 1947 he was certified as an engineering consultant for buildings; his advice on matters of structural theory in conjunction with the building of numerous large hydroelectric plants in Austria was highly regarded. In addition, he taught at the University for Soil Cultivation in Vienna. Graz TH appointed him professor of theory of structures in 1955. A year prior to that, Berlin TU had awarded him an honorary doctorate in recognition of his important scientific work in the field of stability theory and his great achievements in structural steelwork [Chwalla, 1954/2]. Shortly before his death, Chwalla became a member of the Austrian Academy of Sciences in Vienna. Over the years 1925 to 1960 he influenced the theory of stability in steel buildings quite unlike any other person in the German-speaking world, and hence contributed substantially to establishing the science of steelwork in the invention phase of structural theory. His last great work was the comprehensive integration of secondorder theory into the displacement method.

Main contributions to structural analysis:

Das Problem der Stabilität gedrückter Rahmenstäbe [1934/1]; Drei Beiträge zur Frage des Tragvermögens statisch unbestimmter Stahltragwerke [1934/2]; Über das ebene Knickproblem des Stockwerkrahmens [1941]; Einführung in die Baustatik [1954/1]; Ansprache und Vortrag anläßlich der Ehrenpromotion an der Technischen Universität Berlin-Charlottenburg [1954/2]; Die neuen Hilfstafeln zur Berechnung von Spannungsproblemen der Theorie zweiter Ordnung und von Knickproblemen [1959]

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. 722