Structural response in thin-walled steel structures subjected to dynamic loading
Publicerad
Författare
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
As Swedish cities become increasingly dense, the distance between transportation
routes and adjacent buildings decreases, heightening concerns about the potential
effects of exceptional events on nearby structures, such as explosions originating
from transport corridors. Structural members designed for static loads may not
be suitable for dynamic loads from explosions. An example of such a structural
member is corrugated sheet metal (CSM), commonly used in roofing applications.
CSM falls into the category of thin-walled elements, meaning that it has a limited
load capacity due to buckling. This also limits the capacity to resist dynamic loads
from explosions, posing a risk to the overall structural integrity of the building.
Current calculation methods may be overly conservative due to simplified and/or
limited understanding of the post-buckling behaviour of CSM.
This thesis aims to investigate the structural response of thin-walled steel structures
subjected to static and dynamic loading. Simplified models, consisting of
steel plates classified into various cross-section categories and subjected to axial
loading under both static and dynamic conditions, were employed to explore the
fundamentals of dynamic buckling. Once the fundamentals of dynamic buckling
had been investigated, a more complex geometry was analysed, involving a simplified
CSM section. The methodology is based on numerical analyses conducted
using the finite element software Abaqus CAE. The results were validated through
comparison with analytical expressions derived from the Eurocode.
Findings from numerical analyses reveal that the structural response of both the
steel plates and the CSM strip is primarily governed by buckling. At higher
loading rates, the material exhibits a rate-dependent strengthening effect evident
as an increased critical buckling load in the steel plates and reduced deflection in
the CSM strip. Inertia effects, manifested as dynamic oscillations, become more
pronounced at elevated strain rates, with their onset occurring earlier for slender
structures. Increased slenderness and/or initial imperfections lead to a reduction
in load-bearing capacity. Additionally, larger initial imperfections contribute to
reducing the amplitude of dynamic oscillations.
Beskrivning
Ämne/nyckelord
Steel plate, Buckling, Dynamic buckling, CSM, Explosions, Non-linear FE-analysis, Impulse load, Static loading, Dynamic loading