| Economic factors often require that old riveted bridges function longer than originally anticipated. Although current standards indicate that many riveted bridges have exceeded their theoretical fatigue design lives, it is known that this conclusion is often conservative. An improved understanding of the fatigue behaviour of riveted connections is required so that costly premature bridge repairs can be avoided and an appropriate level of safety can be maintained.; Fatigue tests were conducted on full-scale riveted tension diagonals taken from a railway bridge. The experimentation showed that connections in which rivets are subject to bearing have reduced fatigue strength, and that the effect of staggered rivet patterns is significant. The members tested exceeded the fatigue strength of the American Railway Engineering Association Category D. Structural models for the bridge, assessed through comparison with measured strains, showed that a simple truss model can be used to provide an adequate description of the behaviour of the diagonals for use in the calculation of remaining fatigue life. An effective technique for the repair of fatigue cracks in this type of member was also developed. |
