LAUSR

Structural hollow profiles are widely used for steel constructions. To protect such profiles against corrosion, normally they are hot dip galvanized. In this case of failure, a broken support of a staircase was detected. The used hollow profile (150 x 150 x 8 mm, material S355J0) depicted in Figure 1 contains a crack located at one corner and extending over the whole profile length (approx. 6 m). As can be seen from Figure 1 there is a certain distance between the crack flanks. After cutting out the fracture sections, the parts show a distinct curvature (Figure 2a). From this can be concluded that residual stresses in circumferential and longitudinal directions are prevalent.