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 increasing train loads, it is desirable to improve the procedures available for the assessment of fatigue-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 UKtypical bridge configuration and the resulting stress histories are converted into stress ranges using the rainflow algorithm. By comparing the resulting S-N damage, the extent to which connection fixity can affect fatigue life predictions is quantified and ranking of fatigue-critical details is undertaken.