Quantification and localization of internal pipe damage

Internal pipeline defects are detectable and locatable from guided acoustic wave reflections using sensors mounted on the outer wall of a pipe. We demonstrate pipeline integrity monitoring with only two single acoustic sensors. Multi-mode dispersion imaging of shear displacement shows that the pure torsional mode is the only wave that survives axisymmetric pipe reflection. A reduction of 20% of the reference reflection is measured for a damage of half the wall thickness. This natural filtering is used to quantify and locate internal pipe damage.