Stainless Steel Bridge Girders with Corrugated Webs - A parametric study to investigate the sensitivity of Stainless steel girder’s shear behaviour to intial imperfection
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Examensarbete för masterexamen
Program
Modellbyggare
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Sammanfattning
Steel bridges are prone to corrosion, and over the lifetime of the bridge, corrosion is
likely to necessitate maintenance work, re-painting, and inspections. Stainless steel,
on the other hand, is more corrosion-resistant material and can help to reduce the
problem’s negative impacts. Moreover, as these structures are deep in web height,
it is common to use thin webs in steel bridges to prevent utilizing a lot of material
and get the highest strength out of the material with a minimal amount of weight.
The method of manufacturing, however, is complicated due to the thin thickness.
To overcome this problem, corrugated webs, which are lighter than traditional flat
web steel girders, are used. This kind of Thin shell element, on the other hand, is
susceptible to initial imperfection.
The aim of this master’s thesis is to research the shear behavior of bridge gird ers with stainless steel corrugated webs and their sensitivity to initial imperfection.
This is done by, firstly, a literature review to decide the most influential parame ters on the shear capacity of bridge girders with corrugated webs. Secondly, using
ABAQUS software, a sensitivity analysis to initial imperfection is investigated by
varying the shape and amplitude of initial imperfection on three different girders.
Single eigen shapes and various combinations of eigen shapes have been considered
as the shape of the initial imperfection. Hw/400, Hw/300, Hw/200, and Hw/100 are
used to estimate the amplitude. Thirdly, a limited parametric study, by changing
one-factor-at-a-time, has then been performed to see the effect of each dimensional
parameter on the girder’s shear capacity. Finally, the shear capacity of the in vestigated girders has been compared to the shear capacity provided by Eurocode
equations.
The results show that the shear capacity of bridge girders with stainless steel corru gated webs is sensitive to both initial imperfection shape and amplitude. The shear
capacity decreases significantly with increasing initial imperfection amplitude. In
addition, the most critical initial imperfection shape is a single-mode shape of Eigen
shapes and not the first positive mode shape. Web height, web thickness and cor rugation depth significantly increase the shear capacity. Flat fold length decreases
the shear capacity. However, the shear span has a negligible effect. Finally, using
the design curve of Eurocode with the first buckling mode and initial imperfection
amplitude of Hw/200 is on the safe side.
Beskrivning
Ämne/nyckelord
Corrugated web, Shear capacity, Stainless steel, , Steel bridges, Initial imperfection,, Sensitivity analysis, Parametric study