ABSTRACT
Owing to their peculiar destination of use, steel constructions such as bridges or offshore constructions are often placed in aggressive environments. In such cases, the combined action of cyclic loadings and material degradation can lead to sudden corrosion fatigue (CF) collapse if structures are not properly protected. In the present work, a simplified technique to assess the cyclic performance of steel constructions located in aggressive environments is introduced. The presented methodology relies on the concept of “critical corrosion degree” η*Rd, i.e. the minimum rate of corrosion which induces fatigue collapse for a given target service life t*. Accordingly, CF checks can be hence expressed in a “demand vs. capacity” form more in line with principles of performance-based engineering. An existing railway riveted bridge located in Italy in hence selected as a case-study to provide a first application of the presented procedure with regards to a full-scale existing structure. Finally, parametrical analyses are presented in order to highlight the sensitivity of predicted cyclic performance to physical and mechanical variables governing corrosion fatigue phenomenology.
