Civil Engineering Reference
In-Depth Information
According to EC3 [1.27,2.11], the design value of the shear force V Ed at
each cross section shall satisfy
V Ed
V c , Rd 1
:
0
ð 3
:
43 Þ
where V c,Rd is the design shear resistance. For plastic design, V c,Rd is the
design plastic shear resistance V pl,Rd calculated using Equation (3.44) :
A v f y =
p
V pl , Rd ¼
ð 3
:
44 Þ
g M0
where A v is the shear area, which can be taken conservatively equal to h w t ,
and h w and t are the height and plate thickness of the web, respectively.
EC3 (3.6) provides the rules for shear resistance of plates considering
shear buckling at the ultimate limit state where the panels are rectangular;
stiffeners, if any, are provided in the longitudinal or transverse direction
or both; all holes and cutouts are small; and members are of uniform cross
section. Plates with h w / t greater than 72
e
p
e for an unstiffened web, or 31
k t
for a stiffened web, should be checked for resistance to shear buckling and
should be provided with transverse stiffeners at
the supports, where
f q , where f y is the yield stress in MPa. h w is shown in Figure 3.19
and k t is the minimum shear buckling coefficient for the web panel as given
in Annex A of EC3 [ 3.5 ]. The National Annex will define . The value
¼ 1.2 is recommended for steel grades up to and including S460. For
higher steel grades,
235
e ¼
¼ 1.0 is recommended. For unstiffened or stiffened
webs, the design resistance for shear should be taken as
V b , Rd ¼V bw , Rd + V bf , Rd
f yw h w t
p g M1
ð 3
:
45 Þ
in which the contribution from the web is given by
w w f yw h w t
p g M1
V bw , Rd ¼
ð 3
:
46 Þ
For webs with transverse stiffeners at supports only and for webs with
either intermediate transverse stiffeners or longitudinal stiffeners or both,
the factor w w for the contribution of the web to the shear buckling resistance
should be obtained from Table 3.20 according to EC3 based on the type of
end support as shown in Figure 3.23 . The slenderness parameter l w
in
Table 3.20 should be taken as
 
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