Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 173

The verification should be performed as follows:
V Ed
V b , Rd 1

: 0 ð 3 : 51 Þ

where V Ed is the design shear force including shear from torque.

3.8.5 Plate Buckling Effects Due to Direct Stresses
3.8.5.1 General
Steel plate girders are vulnerable to buckling owing to direct stresses. As an
example, plate girder panels at midspan where maximum bending moments
are expected are likely to fail due to mainly pure bending stresses. Design
rules accounting for plate buckling effects from direct stresses at the ultimate
limit state are covered by EC3 [ 3.5 ] . Rectangular panels should be provided
by stiffeners in the longitudinal or transverse direction or both to avoid plate
buckling. The resistance of plated members may be determined using the
effective areas of plate elements in compression for class 4 sections using
cross-sectional data ( A eff , I eff , and W eff ) for cross-sectional verifications
and member verifications for column buckling and lateral torsional buckling
according to EC3 [ 3.5 ] . Effective p areas should be determined on the basis of
the linear strain distributions with the attainment of yield strain in the mid-
plane of the compression plate. In calculating longitudinal stresses, the com-
bined effect of shear lag and plate buckling should be taken into account.
The effective area A eff should be determined assuming that the cross section
is subject only to stresses due to uniform axial compression. The effective
section modulus W eff should be determined assuming the cross section is
subject only to bending stresses. The effective p areas of flat compression ele-
ments should be obtained using Table 4.1, given by EC3, for internal ele-
ments and Table 4.2, recommended by EC3, for outstand elements. The
effective p area of the compression zone of a plate with the gross cross-
sectional area A c should be obtained from the following:
For internal compression elements,

l p 0

r¼ 1 : 0 for : 673 ð 3 : 52 Þ

r¼ l p 0

: 055 3 + c ð Þ

l p >

1 : 0 for 0 : 673, where 3 + c ð Þ 0

l p

For outstand compression elements,

l p 0

r¼ 1 : 0 for : 748 ð 3 : 53 Þ