AD 377 Placement of headed stud shear connectors in troughs of profiled steel sheets with a central stiffener

摘要

Some types of profiled steel sheets (PSS) have a central stiffener in the trough, which makes it impossible to place the headed stud(s) centrally in the trough. This advisory desk note clarifies the existing guidance regarding the position of studs in the troughs of PSS with central stiffeners. Clause 6.6.5.8(3) of BS EN 1994-1 -1:2004' states that in this case the studs should be placed alternately on the two sides of the trough ('favourable' and 'unfavourable'positioning), throughout the length of the span. SCI has already provided guidance in revised Publication P3002 (Section 5.3.1 on page 68/69 and Figure 5.9 (a), (b) and (c)) and NCCI PN001 a-GB3 that complements BS EN 1994-1 -1:2004 provisions, by advising that the studs should be placed in the'favourable' side of the trough (Figure 5.9 (c) of SCI P300) in order to have the best possible results in terms of resistance and ductility.'Favourable'is defined as the side of the trough closer to the nearer support so that the zone of concrete in compression in front of the stud is larger than that behind the stud.This requires a change in stud position at mid-span of a uniformly loaded, simply supported beam. It is believed that the reason why this was excluded from BS EN 1994-1-1:2004 was related to the possible errors that might occur on-site with regard to identifying the'favourable'side for welding the studs. It is also considered that the proposed 'staggered'arrangement (Figure 5.9 (b) in SCI P300), in which pairs of studs are welded on the 'favourable' and 'unfavourable' sides of the trough, would be equivalent to having two studs placed in the central position.