A CONDITION MONITORING TOPIC

1. A technical seminar on
NON-DESTRUCTIVE TESTING IN
RAILWAYS
Presented by
N.SUDHEER
M.TECH(MACHINE DESIGN)
16481D1509
GUDLAVALLERU ENGINEERING COLLEGE
Sheshadri Rao Knowledge Village, Gudlavalleru, PIN:521356

2. Introduction:
Amongst the different modes of transport,
Railways have their greatest utilization in the
transport of large volumes of heavy and bulk
commodities and passengers over long
distances with safety, comfort and convenience.
So railroads require constant support to
maintain their integrity and operate safely.

3. Role of Non-Destructive Testing(NDT) in
Industries:
NDT is widely used in industries for :
Verification of design quality,
Certification of manufactured products,
Assessment of product degradation, and
Effective repair or replacement during service.
NDT has also been a valuable tool in risk
assessment based on experience.

4. A number of railway components and assemblies
are tested and evaluated using NDT
methodologies, during manufacture for freedom
from unacceptable defects and anomalies.
The major components subjected to various NDT
methods are:
Rails,
Wheels,
Axles,
Bearings,
Welded rail joints, and
Brides, etc.

5. Rail inspection is the practice of examining rail
tracks for flaws. Non-destructive testing (NDT)
methods are used as a preventive and/or predictive
measure against track failures and possible
derailment.
Methods used to detect flaws in rails:
Visual Examination(VE)
Ultrasonic Testing (UT)
Eddy Current Testing (ET)
Magnetic Particle Inspection (MPI)
Radiographic Testing (RT)
Electromagnetic Acoustic Transducer (EMAT)

6. Rails
Rails are the members of the track laid in two
parallel lines to provide an unchanging,
continuous and level surface for the movement
of trains.
To be able to withstand high amount of
stresses these are made of high carbon
steel(HCS).

7. Fig: Rails

8. Fig: Manufacturing of Rails

9. Fig: Cross section of Rail

10. Defects in rails
Piped rail
Bolt hole cracks
Head and web separation
Foot and web separation
Horizontal and Vertical Split Web
Defective Welds
Rail Corrosion

11. Fig: Piped Rail

12. Fig: Bolt hole cracks

13. Fig: Bolt hole cracks

14. Fig: Head and Web Separation

15. Fig: Horizontal split head

16. Fig: Defective welds in rails

17. Fig: Corroded rail

18. Visual Inspection/Testing(VT)
Non-destructive rail testing procedure usually
starts with a visual inspection:
With the naked eye and supported with
mirrors,
Magnifying glasses, and
Artificial light sources experts can recognise
exactly which testing methods should be used.

19. Fig: Visual crack on rail

20. Ultra sonic Testing(UT) of Rails
Ultrasonic Testing (UT) is a non-destructive inspection
method that uses high frequency sound waves
(ultrasound) that are above the range of human hearing,
to measure geometric and physical properties in
materials.
Ultrasound travels in different materials at different
speeds (velocity).
However, the speed of sound propagation in a given
material is a constant.

21. Steps in Ultra sonic Testing
Surface preparation,
Calibration,
Conduct examination, and
Interpretation of results.

22. Irregularities in material and internal faults can
be detected by the ultrasonic testing method.
In the process, areas of the rail that are subject
to faults can be checked through the various
angles of incidence and probe heads.

23. Fig: Ultra sonic Testing

24. Fig: Ultra sonic single-rail tester

25. Fig: Portable Ultra sonic double rail testing equipment

26. Fig: Ultra sonic rail testing truck

27. Eddy Current Testing(ET)
Eddy current inspection uses the principal of
“electromagnetism” as the basis for conducting
examinations. Eddy currents are created through
a process called electromagnetic induction..

28.  When alternating current is applied to the
conductor, such as copper wire, a magnetic
field develops in and around the conductor.
 This magnetic field expands as the
alternating current rises to maximum and
collapses as the current is reduced to zero.
 If another electrical conductor is brought into
the close proximity to this changing magnetic
field, current will be induced in this second
conductor.

29. Fig: Principle of Eddy current Testing

30. Steps in Eddy current Testing
Setup equipment,
Calibrate instrument,
Calibrate probe,
Inspect for indications, and
Monitor the readings.

31. Fig: Eddy current Testing

32. Magnetic particle Testing(MPT)
MPT uses magnetic fields and small magnetic
iron filings to detect defects in components.
The only requirement is that the component
being inspected must be made of a
ferromagnetic material such as iron, nickel, or
some of their alloys.
Ferromagnetic materials are those that can be
magnetized to a level that will allow the
inspection to be effective.

33. Steps in Magnetic Particle Testing
Prepare the part surface,
Apply the magnetizing force,
Dust on the dry magnetic particles,
Gently blow off the excess powder,
Terminate the magnetizing force,
Inspect for indications, and
Resetting the magnetisation.

34. Fig: Magnetic Particle Inspection

35. Fig: Automated quality control system for rails

36. Wheels and Axle
A train wheel or rail wheel is a type
of wheel specially designed for use on rail
tracks.
An axle is a central shaft for a rotating wheel.
A wheel set is the wheel - axle assembly of
a railroad car(locomotive).
Wheels are cast or forged (wrought) and are
heat-treated to have a specific hardness.

37. Fig: Single flanged rail wheel

38. Fig: Double flanged rail wheel

39. Fig: Contact between wheel and rail

40. NDT for wheels and axles
• Ultra sonic inspection,
• Magnetic particle inspection,
• Radiography, and
• Thermography.

41. Fig: Ultra sonic inspection

42. Fig: Ultrasonic Testing on Wheel Set Axles-Probe Head

43. Fig: Ultra sonic inspection of railway wheels
for horizontal position

44. Fig: Ultra sonic inspection of rail wheels for
vertical position

45. Fig:Fully automated System for Magnetic Particle
Inspection of Railway Wheels

46. Fig: Wheel-test line-Complete rail-wheel handling, testing and
measuring system including hardness, laser dimensions,
ultrasonic and magnetic examination

47. Fig: Robotics-assisted thermography at a rail wheel

48. Themographic image of railway bridge

49. Fig: IR Thermography (Thermal Imaging
Cameras Monitor Overhead Lines) in Railways

50. Conclusion
• Non-destructive testing (or) NDT is the use of non-
invasive techniques to determine the integrity of a
material, component or structure.
• These techniques allow for inspection without
interfering with the specimen’s final use.
• NDT has a wide range of applications in industries.
Especially in railway industries, various NDT
techniques such as visual examination, ultra sonic
testing, eddy current testing, magnetic particle testing,
and thermography, etc., plays a vital role to inspect and
monitor the condition of infrastructure effectively.

51. References
 Applications of NDT in rail track - Lee Guan Bin (Nanyang
Technological University, School of mechanical and aerospace
engineering).
 Detection and evaluation of rail defects with nondestructive
testing methods Anika Dey 1, Jochen Kurz 2, Lukasz
Tenczynski 3 .
 Hand book of non destructive evaluation – Charles Hellier
(Mc Graw-Hill publishers).

52. THANK YOU