1 Answers
Guided wave testing is a non-destructive evaluation method. The methodemploys acoustic waves that propagate along an elongatedstructure while guided by its boundaries. This allows thewaves to travel a long distance with little loss in energy. Nowadays, GWT is widely used to inspect and screen manyengineering structures, particularly for the inspectionof metallic pipelines around the world. Insome cases, hundreds of meters can be inspected from a singlelocation. There are also some applications for inspectingrail tracks, rods and metal plate structures.
Although guided wave testing is also commonly known as guided waveultrasonic testing or ultrasonic guided waves or long range ultrasonic testing ,it is fundamentally very different fromconventional ultrasonic testing. The frequency used in the inspection depends on the thickness of the structure, but guided wavetesting typically uses ultrasonic frequencies in the range of 10 kHz to several MHz.Higher frequencies can be used in some cases, but detection range is significantly reduced. In addition, the underlying physics of guided waves is morecomplex than bulk waves. Much of the theoretical background hasbeen addressed in a separate article. In thisarticle, the practical aspect of GWT will be discussed.