Project Concept

The concept of the AxleInspect project is to produce and make available two new NDT inspection tool prototypes for the inspection of solid and hollow axles respectively. For the inspection of solid axles, a 2D annular phased array probe will be clamped on at a static position on the axle end face. Using PAUT negates the need for moving parts, thus improving measurement reliability. The new 2D annular phased array probe will comprise multiple transmit/receive elements arranged in a circular matrix. Using the capabilities of PAUT, ultrasonic beam steering will be used to insonify all the regions of the axle to detect the presence of any transverse cracking on the axle body. This will include insonification of the critical wheel-seat area where cracks can occur as a result of fretting due to the press fit wheels.

The probe will be able to handle different axle types, and will accommodate the different hole end face patterns present on the axle end face by switching on/off groups of elements in the probe array. Inspection of solid axles from their end face will allow in-situ inspection and therefore facilitate more frequent inspection outside the periodic overhaul periods. For the inspection of hollow axles, a combined UT and EM probe will be pushed inside. Mechanised scissor mechanics attachments will accommodate different bore diameters. Combining both UT and EM through data fusion will allow 100% inspection giving coverage for both buried cracking and surface cracking. The inspection system will be designed to inspect various size boreholes in hollow axles making the AxleInspect system versatile. Both inspection prototypes will help safeguard axle integrity in a cost effect manner.

Figure 1.1f: AxleInspect Project concept

Never before has a 2D annular PAUT array probe been used to inspect axles from the end face. As such, the array probe will need to be specially made in order to be applied to different size axle end faces. This will require extensive modelling in order to determine the optimal design before manufacture. The result will be a significant improvement beyond the state-of-the-art. Likewise, a combined UT and EM probe is a novel approach to 100% inspection of hollow axles.

In this project, the research organisations will provide research and development capability to the SMEs for the following:

  • New 2D annular phased array probe. One size “fits all” probe capable of inspecting sold axles types with different end face patterns
  • Combined UT and EM probe capable of inspecting different diameter bore hollow axles
  • UT and EM fusion software for information integration of the two NDT technologies
  • Automatic jig for probe positioning for hollow axle inspection