Navier's 1823 Mémoire: Analyses and observations on displacements and stiffness of suspension bridges
Author(s): |
Dario A. Gasparini
Stephen G. Buonopane |
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Medium: | conference paper |
Language(s): | English |
Conference: | 6th International Congress on Construction History (6ICCH 2018), July 9-13, 2018, Brussels, Belgium |
Published in: | Building Knowledge, Constructing Histories [2 vols.] |
Page(s): | 667-673 |
Year: | 2018 |
Abstract: | Some of the analytical models, quantitative results, and inferences on design in Navier's 1823 Memoire on suspension bridges are examined and assessed. Navier derived a linearized formula for the vertical midspan displacement of an unstiffened cable caused by a small change in cable length or span length. He also predicted the vertical displacement and stiffness of a cable subject to a concentrated vertical load at midspan. Navier's linearized results and inferences are assessed on the basis of results from geometrically non-linear analyses. Navier derived a formula for the effective horizontal stiffness of a vertically loaded cable subject to horizontal wind forces. He also examined the effects of bearing types on displacements of multi-span bridges subject to unequal vertical loads, concluding that pulley-like bearings were not feasible. The influence of Navier's results and inferences on the designs of Charles Ellet and John Roebling is discussed. |