An economical, flexible, magnetostrictive sensor (MsS) probe assembly for use on longitudinal cylindrical structures, for guided-wave, volumetric inspection of the structures is described. The paired flexible plate MsS probes each include a flexible strip of magnetostrictive material that is positioned and/or adhered to the base of a generally flat, flexible, conductor coil assembly, preferably with an elastomeric adhesive. The conductor coil assembly has a core composed of a thin flexible layer of metal and a thin bendable permanent magnet circuit. The flexible core is surrounded by a flat flexible cable (FFC) that is folded and looped over the layers of the core. The exposed conductors at the ends of the FFC are shifted from each other by one conductor spacing and joined together so that the parallel conductors in the FFC form a flat, flexible, continuous coil. The probe assemblies may preferably be utilized in pairs and conformed to match the curved contours of the cylindrical surface of the structure under investigation in a manner that is specifically tailored for wire rope, cable, and anchor rod type applications.
Hegeon Kwun; Albert J. Parvin Jr.; Erika Christine Laiche