Shear wave sensors for acoustic emission and hybrid guided wave testing

A system, comprising:

• a plurality of transducers configured to be disposed on a structure, and
• a controller electrically coupled to the plurality of transducers, the controller including
• a machine-readable storage medium, and
• a processor in signal communication with the machine-readable storage medium, the processor configured to
• store acoustic emission signal data in the machine-readable storage medium when a signal amplitude detected by at least one of the plurality of transducers crosses a threshold,
• cause a pulse generator to pulse at least one of the plurality of transducers to transmit ultrasonic guided wave energy in the structure,
• process at least one guided wave signal resulting from said transmitted ultrasonic guided wave energy to identify at least one of a presence, a location, or a severity of at least one defect in the structure, and
• store the at least one guided wave signal in the machine-readable storage medium.

A method, comprising

• detecting, using a processor and a plurality of circumferentially-polarized d15 shear ring transducers disposed on a structure, a shear horizontal-type acoustic emission in a first frequency band in the structure;
• storing shear horizontal-type acoustic emission signal data in a machine-readable storage medium when an amplitude of the shear horizontal-type acoustic emission detected by at least one of the plurality of circumferentially-polarized d15 shear ring transducers crosses a first threshold;
• and
• calculating, using the processor, a location of a source of the shear horizontal-type acoustic emission in said structure using a source location algorithm, a velocity of the shear horizontal-type acoustic emission in the structure, and the shear horizontal-type acoustic emission signal data.