AUTHENTIC project is composed of two main blocks.
- POD analysis considering the manufactured samples to demonstrate quantitatively that Thermography for inspection is better than traditional FPI.
- Development of the inspection system and the final demonstration.
To carry out POD calculations all samples were measured through Thermography, Standard Fluorescent Penetrant Inspections, Microscopic Images, Extended FPI and Computer Tomography.
The thermographic measurements have been evaluated directly by an inspector using a processed image, and using detection algorithms. During measurements, these relevant aspects were considered:
- Manufacturing of the samples with defects with a Varestrain Test Machine
- Representative crack size and distribution
- A realistic crack length/depth ratio
The results of the a90/95 values were the following:
- Cast inconel 718, TIG welds: 0.862
- PBF inconel 718, Laser welds: 1.382
- Cast Haynes 282, TIG welds: 1.288
Final Demonstration of the developed Inspection System was carried out at LORTEK with an aeronautical component part provided by GKN. For that, it was necessary to consider an adequate fixing of the component, and design and manufacture the necessary robot heads (with the corresponding inductor).
Two robot heads and an adequate fixing for the component for thermography were designed and manufactured. The first head can perform inspections on welds with easy accessibility, while the second robot head with special infrared mirrors is aimed at the ‘inner’ welds, located in between the vanes. Both robot heads use the same inductor, which allows crack detection in any orientation, and has led to a patent application.
The CAD designs of both robot heads and fixtures are fed into a CAD-CAM software to virtualize the inspection cell and calculate inspection trajectories. The virtual environment allows:
- Compute total inspection times
- Check that neither the robot head nor the inductor crash in the inspection cell
A text file is also generated to specify the thermographic parameters needed for each point. They are introduced in the Inspection Interface developed and the inspection can be executed. All the information can be seen in a web interface developed by Lortek that allows the inspector to revise all inspection results, and if the system has ignored a defect (false negative), the inspector can update and correct it. These changes are automatically stored in the system. In this way, they can be introduced into the re-training of the automatic defect detection models later.
Four exploitable results were generated related to the new induction thermograpy based NDT system, leading to a patent. Several dissemination actions were carried out, including project webpage, partners' webpages, many posts in LinkedIn and Twitter, a journalistic article, 4 conferences and 3 scientific publications.
