Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 187

where g v is the partial factor; d is the diameter of the shank of the stud,
16 d 25 mm; f u is the specified ultimate tensile strength of the material
of the stud but not greater than 500 N/mm 2 ; f ck is the characteristic cylinder
compressive strength of the concrete at the age considered, of density not less
than 1750 kg/m 3 ; and h sc is the overall nominal height of the stud. The value
for g v may be taken as 1.25.
(b) Composite beams with profiled steel sheeting
The experimental investigations, highlighted in Section 2.6 of
Chapter 2 , for headed stud shear connectors in composite beams with pro-
filed steel sheeting show that the shear resistance of headed studs is some-
times lower than it is in a solid slab, for materials of the same strength,
because of local failure of the concrete rib. For this reason, EC4 [2.37] spec-
ifies reduction factors, applied to the resistance P Rd to determine the capac-
ities of headed studs in composite beams with profiled steel sheeting as
follows:

81 Þ
where ( P r ) is resistance of a stud in a trough and k is the reduction factor that
depends on the direction of sheeting.
For sheeting with ribs parallel to the beam, the factor ( k l ) is calculated as
follows:

P r ¼ kP Rd ð 3 :

6 b o
h p

h sc
h p 1

k l ¼ 0 : ð 3 : 82 Þ

where the dimensions b o , h p , and h are illustrated in Figure 2.15 and h sc is
taken as not greater than h p +75 mm. EC4 rules are discussed by Johnson
and Anderson [2.40]. Systematic theoretical and finite element studies since
1981, mainly by Oehlers [2.51] and initially for solid and haunched slabs,
have been extended to parallel sheeting.
For sheeting with ribs transverse to the beam, the factor ( k t ) is calculated
as follows:

0 : 7

n r

b o
h p

h sc
h p 1

k t ¼ p ð 3 : 83 Þ

where n r is the number of connectors in one rib where it crosses a beam, not
to be taken greater than 2 in calculations. It is recommended that off-center
studs should be placed on alternative sides of the trough, but no other account
was taken of the important influence of dimension ( e ) in Figure 2.15.
The reinforcement in a composite slab is usually a light welded mesh.