Using Saint Venant’s Elements in Multibody Archeological Studies

Abstract

In 2015 different IAVSD colleagues received the George Stephenson gold medal for a paper [1] dedicated to the study of interaction between railway multibody models and track structures with the help of modern dynamic softwares. This has been an occasion to have a look at the life of George Stephenson and his contribution to railways. A set of questions appear: how did he manage stability? How did the engineers for all the different models developed during the steam century? The stability theory has been established only by authors like Rocard during the beginning of the 20th century: could it be possible today to design quickly, as did the ancients, a new locomotive from scratch? And consequently, are we more efficient with our multibody simulation tools than the ancient engineers? Or simply, can we estimate today the stability or curve behavior of these vehicles? The studies of different old vehicles led to the remark that unsymmetric and non-linear mechanisms, particularly dry friction elements, were key points of theses mechanisms, step by step replaced by symmetric and smoothed linear design. Fortunately, the use of Saint Venant’s elements, defined a little later but during the 19th century, is still efficient to represent and simulate the early railway age vehicles.