Diaphragm Splicing Deviation in Steel Bridge Deck: Effect on Fatigue Performance and Its Preventive Measures

Abstract

Asymmetric scallop cutouts on the sides of a U-rib caused by diaphragm splicing deviation were detected in a bridge. To study the possible effect of this phenomenon on fatigue performance, the stresses of the asymmetric scallop cutout and the diaphragm-to-rib weld were tested, and the influence was compared with that of the symmetric case. This and numerical simulation showed that, for the side of the U-rib with the smaller-radius scallop cutout, the position of stress concentration transferred from the scallop cutout to the diaphragm-to-rib weld, and the stress value of the weld was greater than that of the scallop cutout, resulting in more fatigue damage to the weld. To reduce the adverse effect caused by the asymmetric scallop cutouts, an application experiment with a hammer peening was carried out, and the stresses before and after hammering were monitored. The results showed that hammer peening could improve the fatigue performance by inducing compressive stress.