Kraftgrößenverfahren und Deformationsmethode im Licht der Habilitationsschrift von Georg Prange (1885-1941)

Force Method and Deformation Method in the light of Georg Prange's (1885-1941) Habilitation Thesis.

At the end of the 19th and at the beginning of the 20th century different computing methods have been developed for the structural analysis of frames, which today are called "force method" and "deformation method". Heinrich Müller-Breslau was the pioneer of the force method whereas the deformation method was combined with the name of Otto Mohr. It was not clear for them, whether the bases for both methods were equivalent. Only Georg Prange was able to show, that the variational principles behind both methods could be transformed into each other by a Legendre transformation.
Today it can be shown by Prange's habilitation thesis why finite-element-methods almost exclusively are based on the deformation method, working with deformations as unknown variables.