Dispersion and attenuation by transmission,reflection, and mode conversion in welded pipes

Torsional wave dispersion and attenuation in an open empty welded pipe are determined from a multi-receiver position reflection experiment. The fundamental torsional wave is dominantly reflected at the free end and the converted non-axisymmetric flexural modes are naturally attenuated. The resulting phase velocity contours are in agreement with theoretical predictions. The transmission losses are quantified and compared to those reflective elements associated with end and weld reflection. At any reflective node, the incident wave is split between back and forward preserved mode scattering (“reflection/transmission”), conversion to other modes plus energy lost by absorption. The ratios for each element are quantified.