Civil Engineering Reference
In-Depth Information
Figure 7:
Detailing of reinforcement in composite girder with RC-slab and composite
dowels
(iii) Steel failure
For small plate thickness and low steel strength, steel failure of the steel dowel can occur.
This failure mode is caused by a combined shear-bending mechanism, which leads to a hori-
zontal crack in the steel plate. Due to the ductile behavior of structural steel, this failure mode
goes along with large plastic deformations and is therefore ductile (“Fig. 8”).
Figure 8:
Test specimen with steel failure: plastic deformation (left) and static crack
(right)
The basis of the mechanical model is von Mises yielding in a critical section, where
stresses due to the shear force
P
2
and the bending moment due to
P
2
∙z
p2
occur. The position
of the critical section is an extremum problem of decreasing cantilever
z
p2
and decreasing
load
P
2
as well as a decreasing section area (“Fig. 9”). Based on this mechanical model the
characteristic bearing capacity is expressed by:
(5)
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