Steel cables have been widely used in cable-stayed and suspension bridges since 100 years ago. Visual inspection for these bridges can be difficult, expensive, dangerous, and disruptive. Thus, acoustic monitoring has recently been applied to existing bridges as a non-intrusive inspection method. In this study, acoustic emission (AE) was used to understand and establish the correlation between fracture of a 20 ft. long high strength steel cable strand of seven wires and its induced acoustic feature. Strain gauges were deployed along the length of individual wires to understand the strain redistribution as a result of wire breakage and determine the influence length of the steel cable under tension. AE monitoring parameters (e.g. hits, energy, and counts) were utilized for fracture detection and localization. AE signals were also characterized with time-frequency analysis to understand the effects of different noise sources. Test results indicated that, strains along each wire of the cable change dramatically before and after each wire fracture, and the influence length of such a fracture is expected to be approximately 45 ft. when the cable is loaded below 35% of its breaking strength. AE was demonstrated to be an effective technique for wire fracture detection and localization.
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