Fatigue Performance of Welded Steel Girders with Corrugated Webs
Typ
Examensarbete för masterexamen
Program
Publicerad
2020
Författare
Save, Erik
Åkermo, Karl
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Steel girders with corrugated webs have been widely studied regarding their static
capacity. They are known to have high out-of-plane stiffness as well as shear buckling
capacity. This permits the use of deeper web plates without the need for additional
stiffeners. However, an important aspect that has not been studied to a large extent
is the fatigue capacity of these structures. A number of fatigue tests have previously
been performed to determine their fatigue resistance. Those tests have shown
the complexity of the fatigue performance due to the complex geometry and shear
transfer mechanism. One aspect that is argued to influence the stress state is the
transverse bending of the flanges due to shear flow in the web. This effect and its
influence on the structural hot spot stress at fatigue critical points has not been
examined until today and is therefore further investigated in this thesis. This thesis
initially presents a state of the art literature review of previous work on fatigue
performance of corrugated web girders followed by the procedure, results and discussion
of the finite element analyses performed. Evaluation of previously performed
experimental tests shows that the fatigue performance of corrugated web girders is
slightly better than what is currently suggested in the design standard EN 1993-1-9.
Based on the finite element analysis, it is found that the transverse bending of the
flanges has an effect on the structural hot spot stress at the fatigue critical points
and should be considered in fatigue design. A proposal is presented for considering
the structural hot spot stress as a superposition of two parts corresponding to primary
and transverse bending of the flanges. Also, suggestions on how to efficiently
and accurately model a corrugated web girder using finite element method are given.
Beskrivning
Ämne/nyckelord
Corrugated Web , Welded Steel Girder , Fatigue , Finite Element Modelling , Structural Hot Spot Stress , Transverse Bending