Non-destructive Testing of Surface Defect in Railhead

Publicerad: 14 augusti 2017

The goal is to develop an accurate condition monitoring tools to be decision support for rail track maintenance actions.

Sponsor: Trafikverket/JVTC 

Forskare: Rayendra Anandika,Jan Lundberg (PL), Christer Stenström och Matti Rantatalo

Duration: 2016-2020

Phased array ultrasonic testing (PAUT) has been employed to inspect surface cracks in railhead and has been able to measure 2.65 mm depth of real rail surface crack with 17 % accuracy.  The measurement was verified by slicing the railhead into thin pieces with a thickness of 0.65 mm. There were surface crack marks at each of these pieces. These sliced rail pieces then were photographed in a way so that the crack marks from all of the pieces can be reconstructed into a 3D image reconstruction of surface crack. This reconstructed image shows a network of surface crack path underneath the rail surface. From the comparison between this image and PAUT, it seems that PAUT is accurate to be used for estimating the crack depth and the crack profile. Furthermore, to increase the accuracy of PAUT, SAFT post-processing method will also be performed

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Figure 1. 3D image reconstruction of a surface crack in a railhead (unit in mm).
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Figure 2. An example of PAUT on scanning a shallow surface crack in railhead. Red colors represents crack location.