Fatigue Reliability Reassessment Applications: State-of-the-Art Paper

Abstract

The problem of assessing the damage to and remaining life of structures subjected to fatigue is explored, with particular emphasis on railroad bridges, highway bridges, and offshore structures. In railroad structures, the fatigue reliability estimates are typically calculated based on fatigue life predictions. The resulting predictions are used for budgeting purposes rather than for scheduling repairs. Examples are given of economic decision based on fatigue life calculations. Fatigue reliability estimates for highway bridges are also typically based on fatigue life calculations. Target reliability values have been suggested and are used in both the design of new bridges and the evaluation of existing bridges. Given the economics of offshore structures, it is feasible to develop more elaborate fracture mechanics models. These models have the advantage of explicitly allowing updated estimates of fatigue reliability based on inspection results. The economics of inspection of offshore structures also dictates that inspection scheduling be based on fatigue realiability estimates.