Connection fixity effects on stress histories in riveted rail bridges

The riveted type of construction is characteristic of older railway bridges. As some of these bridges approach, or have even exceeded their theoretical fatigue life under in-creasing train loads, it is desirable to improve the procedures available for the assessment of fa-tigue-critical details. The aim of this paper is to present results through the use of the FE method, which address the manner in which assumed conditions of fixity of bridge riveted joints affect the resulting internal stresses. Different degrees of connection fixity, ranging from fully fixed to partially fixed, are assigned to the connections. A nominal train is traversed over a UK-typical bridge configuration and the resulting stress histories are converted into stress ranges us-ing the rainflow algorithm. By comparing the resulting S-N damage, the extent to which con-nection fixity can affect fatigue life predictions is quantified and ranking of fatigue-critical de-tails is undertaken