Model Assisted POD of Laser-Ultrasonics NDT for train axles: a review

Laser-Ultrasonics is a technique seeking for maturity in the NDT for high speed train axles. When questioned for reliability, Probability of Detection (POD) Curves try to build the confidence on the stated method. In the recent period of time much work has been started for changing the conventional method of building POD curves by using Model Assisted POD curves or MAPOD. This method uses a simulated model in replacement real test specimen that is comparatively cheap and quick. In this research work Method of MAPOD curve using a finite element (FEM) code is discussed taking an example of Laser-Ultrasonics for surface defect detection in train axles. It relates the numerical response of FEM to build a validated and trained model for further mocking of the real POD specimen. It further compares the FEM method with general retracing methods being used for POD generation.