Technology Digests / EMAT Sensor/Assemblies
 Endurance Testing

TD24-008

August 22, 2024
Authors
  • Anish Poudel
  • Brian Lindeman
  • Sirius Roybal
  • Beatrice Rael
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Key Findings

  • A first-generation magnetostrictive EMAT sensor achieved 1 million wheel passes in the rolling load machine before being superseded by an improved design.
  • Both versions of the second generation flat magnetostrictive EMAT sensor reached 2 million wheel passes with minimal wear and damage. This number of wheel passes is equivalent to 40 MGT of traffic at 40 kips wheel load.
  • The EMAT sensor signal quality after the RLM tests was as good as the signal quality prior to the test.
  • The EMAT sensor assembly requires the field side of the rail head to be notched approximately 1 inch deep by 5 inches long. After 110 MGT in total passes, the additional vertical wear at the notch averaged 0.01 inch and additional cross-sectional area loss averaged 0.04 inch.

EMAT Sensor/Assemblies
 Endurance Testing

MxV Rail continues its partnership with Innerspec Technologies, Inc. in the development of a magnetostrictive Electromagnetic Acoustic Transducer (EMAT) sensor and assemblies for implementation in revenue service. Previously, MxV Rail conducted proof-of-concept static and dynamic testing in the laboratory to demonstrate the capability of EMAT technology to detect internal wheel indications as small as 0.15 inch and up to 0.25 inch deep.1-3 The work performed in the current phase involved 1) ruggedizing the magnetostrictive EMAT sensor assembly and 2) conducting endurance testing in the rolling load machine (RLM) to evaluate the performance of the magnetostrictive EMAT sensor/assembly, pneumatic actuator, and notched rail under applied dynamic wheel load. The efforts of this phase resulted in the design of an improved sensor assembly that was installed and implemented at the Facility for Accelerated Service Testing (FAST®) track for railcar wheel inspection. BACKGROUND The reliability and durability of wayside sensors and assemblies play…