ABSTRACT
Abstract This paper describes a programme of research concerning the use of Acoustic Emission (AE) as a diagnostic technique for the non destructive evaluation of welded steel bridges. The AE technique provides a method of remote sensing, enabling continuous monitoring of fatigue crack initiation and propagation in steel structures in areas that are difficult to inspect visually. Tests on large scale welded steel plate girders and a six span composite steel plate girder bridge, monitored using AE, are described. Background noise, such as mechanical rubbing at supports, is shown to be distinguishable from stress wave activity generated by fatigue crack propagation and crack face rubbing. It is anticipated that the classification of cracks will lead to the development of an expert system capable of crack location, growth analysis and life prediction. Keywords: Steel bridges, acoustic emission, plate girders, crack location.
