Acoustic emission monitoring of fatigue crack growth in a slender web of bridge girder

摘要

It is demonstrated that the initiation of fatigue cracks can be detected by sud- den increases in cumulative acoustic emission (AE) activities and in AE hit rate, and that the onset of catastrophic failure of structures can be detected by sudden deceases in average hit rate and average AE density. During the progression of fatigue cracks, a good linear relationship is obtained between the cumulative AE hits and the crack increment, and between the average AE hit rate and the average crack growth rate, indicating a po- tential for the quantitative assessment of fatigue crack growth.