Ultrasonic testing with permanently installed transducers is widely used for online corrosion monitoring in the field. In this paper, a carefully optimized ultrasonic corrosion monitoring technique for performing measurements in the laboratory is presented. It is shown that for thickness measurements of a 10 mm steel component, a repeatability of ∼40 nm can be maintained over the period of a day. The technique has been applied to monitoring the wall losses of a steel sample during driven and free corrosion experiments. All ultrasonic wall loss measurements reported have been validated by optical surface profile scans and, where possible, by analytical predictions based on Faraday’s law. Further analysis of the results shows that wall loss rates of the order of 0.1 mm/y to 0.2 mm/y can be detected within 1 h to 2 h. This state-of-the-art laboratory technique is highly accurate and responsive, and possesses the potential for becoming a powerful alternative corrosion assessment tool that is convenient to use.

In this paper, for the first time, the boundary element method (BEM) is used for modelling smart structures instrumented with piezoelectric actuators and sensors. The host structure and its cracks are formulated with the 3D dual boundary element method (DBEM), and the modelling of the piezoelectric transducers implements a 3D semi-analytical finite element approach. The elastodynamic analysis of the structure is performed in the Laplace domain and the time history is obtained by inverse Laplace transform. The sensor signals obtained from BEM simulations show excellent agreement with those from finite element modelling simulations and experiments. This work provides an alternative methodology for modelling smart structures in structural health monitoring applications.