Thibaut Detroux, a researcher at ULg, has just created a software solution that studies vibrations in airplanes. The software is intriguing and interesting in the world of aviation.

His passion dates back to his childhood and his uncle's gift of an introductory flight at Temploux Airfield. That day, Thibaut Detroux was still very far from imagining that many years later the US Air Force, Safran and even Airbus would take a close interest in his work.

This young 28-year-old doctor of applied sciences has just won the award for the Best PhD Thesis in Belgium in Mechanical Engineering. The official title of his work is "Performance and Robustness of Nonlinear Systems Using Bifurcation Analysis".

To summarise his work, it involves developing a software programme which can be used to detect vibrations likely to cause dangerous alterations to a complex structure, like an airplane in sometimes specific conditions.

An aircraft in flight may encounter stronger winds and cross turbulence, it can also accelerate or change altitude abruptly, "these are stress variations that will cause vibrations in the structure", the researcher explains. "A well-known example is the fluttering of wings that occurs when an airplane's speed increases, beginning to vibrate before returning to "rest". But if a certain speed is exceeded, the vibrations increase more and more."

In practice however, you never arrive at the point where the aircraft breaks up in flight. "This is still obviously the exception", smiles Thibaut Detroux. "Air travel is still the safest means of transport... But with recent environmental constraints, engineers are being forced to push aircraft design ever further. They must pollute less and therefore consume less. Making aircraft lighter. They are therefore constructed increasingly leanly and are becoming increasingly slender. And because of these developments, we are seeing vibrations."

His work was therefore to create a software solution that could be used to detect such phenomena for dynamic structures, particularly in the aerospace industry.

"This means aircraft, but also satellites. This is unprecedented in the sense that the literature contains many methods, but which are applied to very simple systems, not to a complex structure such as an airplane." And if the US Air Force and Airbus are following his work, it is because it ensures that the "bifurcations do not occur too early and above all, will not result in disaster for the airplane. A bifurcation being a sudden change in a structure's dynamic.