Ultrasonic guided waves in structural health monitoring

Ultrasonic Guided Wave inspection and structural health monitoring is being considered today in such natural wave guide structures as plates, multi-layer structures, rods, rails, piping and tubing, an interface, and curved or flat layers on a half space. An increased understanding of the basic physics and wave mechanics associated with guided wave inspection has led to an increase in practical nondestructive evaluation and inspection problems. Computing power today is also making dreams come true, where only a vision was possible decades ago. A principal advantage of guided waves is inspection over long distances with excellent sensitivity from a single probe position. There is also an ability to inspect hidden structures and structures under water, coatings, insulations, and concrete. Basic theoretical aspects of dispersion curve analysis, wave structure, source influence, sensor types and instrumentation possibilities and commercialization ventures will be discussed along with a variety of practical applications on ship hull, containment structures, aircraft, ice detection, pipelines, rail, overlap joints, and crystal manufacture. Phased array focusing in pipes and across elbows will be highlighted. Computational aspects of FEM and BEM analysis for defect classification and sizing analysis will be outlined. Future directions of leave in place sensors and wireless activity will also be presented.