Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 172

Table 3.20 Contribution from the Web w w to Shear Buckling Resistance According
to EC3 [ 3.6 ]

Rigid End Post Nonrigid End Post

l w <

0 : 83 =

= l w < =l w =l w 0 : 83 1 : 08 0 : 83 0 : 83

l w 1

7+ l w =l w : 08 1 : 37 = 0 : 0 : 83

e

A e

a

Nonrigid end post

No end post Rigid end post

(a) (b) (c)

Figure 3.23 Types of end supports.

s

f yw
t cr

l ¼ 0 : 76 ð 3 : 47 Þ

where t cr ¼k t s E and the values for k t and s E may be taken from Annex A of
EC3 [ 3.5 ] .
When the flange resistance is not completely utilized in resisting the
bending moment ( M Ed M f,Rd ), the contribution from the flanges V bf,Rd

should be obtained as follows:

<

!

2

b f t f f yf
cg M1

M Ed
M f , Rd

V bf , Rd ¼ 1 ð 3 : 48 Þ

where b f and t f are taken for the flange that provides the least axial resistance,
b f being taken as not larger than 15 et f on each side of the web, and M f,Rd is
the moment of resistance of the cross section consisting of the effective area
of the flanges only calculated as follows:

M f , k
g M0

M f , Rd ¼ ð 3 : 49 Þ

6 b f t f f yf
th 2 w f yw

25 + 1

:

c ¼ a 0 : ð 3 : 50 Þ