25.1 Stud connectors used with profiled steel sheeting
Where profiled sheeting is used, stud connectors are located within con-crete ribs that have the
shape of a haunch, which may run in any direction relative to the direction of span of the
composite beam .Tests show that the shear resistance of connectors is sometimes 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, Euroeode 4 specifies reduction factors ,applied to the resistance pRd found
from equation (2.14)or(2.15).For sheeting with ribs parallel to the beam, the factor is
where Nr is the number of connectors in one rib where it crosses a beam ,not to be taken as greater than 2 in calculations.
These factors are based on formulae developed in North Ameica (25) modified to allow for the recnlts of more recent tests(15.23)on European profiles It is known that they do not provide a uniform margin of safety. More test data are needed to enable them to be improved, and as a basis
for reduction factors for connectors for connectors other than studs. Also a distinction perhaps be made between stud welded to the steel flange through a hole in the sheeting (the usual practice in some countries) and the British (and North America) practice of through-deck welding.