Experimental fatigue evaluation of steel double-angle connections in railway bridges.

摘要

This study was undertaken to evaluate the fatigue strength of double-angle shear connections suggested for new constructions or replacement of old damaged connections in steel railway bridges. The scope of the study was on railway bridges located in southern Nevada which were built around the turn of the century, and are used to transport high level of nuclear waste to the proposed repository at Yucca mountains. During their lifetime, they have been subjected to millions of cyclic loading caused by the train passages over the bridge and are thus prone to the effect of fatigue damage.; Two full-scale specimens were built and tested under an artificial cyclic loading of +/{dollar}-{dollar} 44 kips representing the equivalent load which produces a total shear reaction at the connection similar to the one in the actual bridge. However, in real bridge, the load cycles from 0 to 88 kips. Results of testing included determining the fatigue life of the specimens, and indicated that the connections are prone to the effect fatigue damage by exceeding the endurance stress limit at some locations. The results also included determining the amount of transferred moment through the double-angle shear connections, which are commonly assumed to act as pin connections in transferring only shear force, and the effect of stress concentrations on increasing the stresses around the connection holes. The theoretical results of the modeled specimens on ADINA program were confirmed by a comparison to the experimental results.