Magnetostrictive EMAT for in-motion inspection of railroad wheels

Abstract

This disclosure relates to the inspection of train wheels while mounted on a train that is moving on a railroad track. A magnetostrictive EMAT transducer is built using an RF Coil, a static biasing magnetic field, and a strip of highly magnetostrictive material. This magnetostrictive EMAT transducer is subsequently attached to a rail on the track so the wheel tread of the moving train can contact and apply downward pressure on the magnetostrictive EMAT transducer. A mechanism under the transducer provides enough counterforce to pressure-couple the transducer with the tread of the wheel. Once the transducer is ultrasonically coupled with the wheel, an ultrasonic instrument sends a pulse to the transducer generating a Shear Horizontal wave that travels circumferentially following the tread body. The Shear Horizontal wave generated with this magnetostrictive strip EMAT transducer penetrates deep into the wheel tread and permits detection of both surface and internal defects.

Dependencies are inferred from the claim text.