Two MSc projects in thermal non-destructive testing
NDT using thermography, that is, non-destructive testing using a thermal infrared camera, has
recently become increasingly interesting for the automotive and aerospace industries where high
quality and low structural weight are driving factors.
We are interested in TNDT for inspecting spot welds and for finding subsurface cracks.
In short, the method works as follows (see also the figure below). A strong flashlight heats (excites)
the surface at the location of the spot weld to be inspected. The material will cool faster where a
spot weld dissipates the heat, and the cooling process will be observed during 1-2 seconds with a
thermal camera. The acquired thermal image sequence is then analyzed and the spot weld
characterized.
Similarly, the method can be used for finding subsurface cracks or defects by analyzing the thermal
image sequence, since the heat will dissipate from the surface faster where the metal is solid than
where a crack is present.
We are currently looking for two students; one focusing on crack detection and one on spot weld
characterization. Both projects aim at comparing simulations and measurements of the described
processes and evaluating existing methods for detection/characterization.
1. Study of available literature, measurement data, and simulation models.
2. Tuning of simulation models (Comsol) to fit measurement data.
3. Development of sensor simulation model (Matlab) in order to produce simulated thermal
images.
4. Run and evaluate existing defect detection (C++ or Matlab) / spot weld characterization
(Matlab) methods. Identify shortcomings and propose improvements.
For further information, please contact Jörgen Ahlberg at Termisk Systemteknik, Ph: 0706-75 73 84,
E-mail: Jörgen Ahlberg, jorgen.ahlberg@termisk.se