The structural assessment of existing steel structures in accordance with DIN EN 1993-1-5 and DIN EN 1993-1-3 is often challenging or, in some cases, not feasible. These standards are primarily based on modern construction methods, materials, and fabrication quality, which may differ significantly from those found in existing structures. At the same time, there is an increasing need for reliable assessment methods in both bridge and building construction, particularly in the context of major infrastructure projects and the ongoing energy transition, which requires many existing buildings to be assessed and potentially strengthened for the installation of photovoltaic systems.

However, gaps in the current design provisions make it difficult to assess thin-walled, stiffened, and cold-formed steel members, whose original design may no longer satisfy current requirements. The proposed research project aims to address these limitations through a combination of experimental and numerical investigations. Improved buckling verification methods will be developed based on imperfection-dependent buckling curves, considering compression, bending, and shear loading.

The research will be supported by measurements of geometric imperfections obtained from existing bridge and building components. These data will be statistically evaluated and incorporated into probabilistic models to establish representative and reliable imperfection characteristics. The resulting imperfection models will also be developed for application in advanced numerical design methods, including finite element simulations, thereby enabling a more realistic and reliable assessment of existing steel structures.

University of Stuttgart
Institute of Structural Design
Univ. Prof. Dr. sc. techn. habil. Markus Knobloch, Univ.-Prof. Dr.-Ing. Ulrike Kuhlmann,
Ainaz Sultangirova, M.Sc.

TU Dortmund University
Chair of Steel Construction
Prof. Dr.-Ing. habil. Bettina Brune, Univ. Prof. Dr.-Ing. Dieter Ungermann,
Michael Diener, M. Sc.

The German Committee for Steel Construction DASt

01/07/2025 – 30/06/2027