Technology Digests / Evaluating Electromagnetic Field Imaging for Use in RCF Crack Depth Analysis

TD23-004

July 17, 2023
Authors
  • Anish Poudel
  • Kenny Morrison
  • Brian Lindeman
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Key Findings

  • The fourth generation EMFI flat sensor was tested under controlled conditions to assess accuracy and repeatability.
  • Run-to-run testing demonstrated a high correlation among five runs for the same and different speeds with runs within the same speed having the highest correlation.
  • Pre- and post-grind crack depth trends were generally captured by the EMFI system, but an exact value is difficult to state due to fundamental differences in measurement techniques.
  • The EMFI crack depth values between 0 and 0.5 mm are insignificant at the liftoff where the sensor is currently being operated. These crack depths can be affected by grinding marks and are within the error band of the EMFI sensor.

Evaluating Electromagnetic Field Imaging for Use in RCF Crack Depth Analysis

As part of the Association of American Railroads’ (AAR) Rail Inspection Technology Strategic Research Initiative (SRI) program, MxV Rail has been working with Athena Industrial Services, Ltd. of Calgary, Alberta, Canada, to facilitate the development of an electromagnetic field imaging (EMFI) nondestructive evaluation (NDE)-based, field-deployable inspection system for characterizing rolling contact fatigue (RCF) crack depth on the running surface of rails. MxV Rail conducted several in-motion tests to evaluate the technology readiness of EMFI for future deployment on North American railroads.  In prior work,1-3 Athena developed several iterations of the inspection software for the EMFI sensor and a calibration procedure for the EMFI probe explicitly designed for rail head inspections. As a result, significant improvements were made in the EMFI calibration and data analysis methodologies. The work performed for this phase involved performance and accuracy testing of Athena’s fourth-generation rail scanning sensor and software, trade named the RAGA system from…