Replacement Decision Of Bridge Girder Of A Working EOT Crane Based On Fatigue Life Calculation

Bridge girder is an important structural member whose fatigue life decides the life of an EOT crane. In this paper, the fatigue life of bridge girder of a working EOT crane is calculated based on Palmgren & Miner’s rule for the important decision of replacing or maintaining the girder. The variable loadings coming on the bridge girder at the exact loading points of a working crane and stress spectrums by reservoir counting method are presented. A working crane of class of duty 4 as per BIS “M8” commissioned in 1983 is selected for this. The fatigue life considering probabilistic survival of 97.5% comes out to be 25.68 years. It is suggested that the bridge girder has lived its fatigue life and needs replacement.