Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 174

r¼ l p 0

: 188

l p >

1 : 0 for 0 : 748

l p

where

s

f y
s cr

b

= t

l p ¼

¼

4 e

p ð 3 : 54 Þ

28 : k s

where c is the stress ratio used in Tables 4.1 and 4.2, b is the appropriate
width, and k s is the buckling factor corresponding to the stress ratio c
and boundary conditions. For long plates, k s is given in Table 4.1 or
Table 4.2 given in EC3 [ 3.5 ] as appropriate, t is the thickness, s cr is the elastic
critical plate buckling stress, and e ¼

f q , where f y is the yield stress in MPa.
According to EC3 [ 3.5 ], for aspect ratios a/b

235

1, a column type of buckling
may occur (see Figures 3.24 and 3.25 ) , and the check should be performed

<

b

a

Figure 3.24 Definition of aspect ratio a¼a/b of rectangular plates.

Column-like behavior of plates
without longitudinal supports

Column-like behavior of an unstiffened
plate with a small aspect ratio a

(b)

(a)

Column-like behavior of a longitudinally
stiffened plate with a large aspect ratio a
Figure 3.25 Column-like behavior according to EC4 [ 3.6 ] .

(c)