Hannah Franz, PhD student at Centrale Nantes, awarded the René Houpert 1st Prize from the Association Universitaire de Génie Civil (AUGC)

Hannah Franz is a PhD student at the SIS Doctoral School and Centrale Nantes. She is carrying out her PhD work at the Université Gustave Eiffel (UGE) in Bouguenais.

Hannah follows in the footsteps of Mickaël Le Vern (in 2021) and Victor Poussardin (in 2022), making this the third consecutive year that a Centrale Nantes and ED SIS (ex. SPI) PhD student, working at the UGE (ex-Ifsttar), has won this first prize.

Hannah's research focuses on assessing the structural performance of riveted lattice beams in metallic railway concourses from 1850-1930. The aim of her thesis is to improve our knowledge of the structural behavior of 19th and early 20th century steel structures, in order to facilitate the implementation of appropriate dimensioning and reinforcement methods during renovation or reuse projects. The study focuses on riveted lattice girders used in roof structures, in particular those of railway concourses. These beams are regularly reinforced to compensate for the numerically identified risk of buckling, whereas in reality, excessive deformations linked to instabilities are rarely observed. The thesis draws on both structural mechanics and construction history to:
 

• take stock of the specific features of riveted lattice girders
• improve our understanding of their behavior by comparing historical and current design methods,
• characterize the rotational stiffness of riveted joints and its influence on the buckling risk of lattice girders, and finally
• identify the most appropriate strengthening methods.

Her work is based on the exploitation of calculation notes and structural plans from historical archives and recent renovation projects, on numerical structural analyses, and on an experimental campaign consisting of vibratory and quasi-static tests on old riveted lattice girders recovered from a demolition site.

► Learn more about the René Houpert prize (in French)