Ultrasonic Guided Wave Phased Array Inspection of Pipelines

Piping systems are often inspected ultrasonically to ensure afety. This can be accomplished by a series of point to point tests from the out ide surface of the pipe. If coating cover the pipe, as is often the case, access LO the outside surface requires removal
of the coating to perform the test, and then re-installation when testing is complete. Removal and reinstallation of coating is
not only time consuming but in most cases it is prohibitively expensive too. Ultrasonic guided waves provide an attractive
alternative solution to the basic bulk wave ultrasonic test. Using Guided Waves, a probe can be applied to the pipe at a single
location and several meters of the pipe can be in pected. The coating is only removed where the probe is applied. This paper
describes the visco-elastic properties of two different coating materials: Bitumen tape and wax tape is considered, an FEM
simulation of the propagation ofaxi ymmetric guided wave through bare and coated pipes having different coating thicknesses.
The ABAQUS FEM code is used and validation of FEM simulation re ult through experiment in bare and coated pipes using
guided wave inspection sy tern is reported.