Engineering

Eco-friendly Optical Measurement for Aircrafts

Oversize components are heavy, when fibers where introduced into aeroindustry nobody knew exactly how to calculate stress on this materials in assemblies along with other materials. Darmstadt scientists know now thanks to optical measurement methods to the thousandths of a millimeter precision can be use. Now, the components of the future can be significantly slimmer and therefore even easier to carry by plane.

Where aircraft manufacturer with carbon fiber insert reinforced composites (CFRP) to save weight and therefore fuel. by precaution components are significantly oversized because are not sure predictable is the reaction of high-strength and lightweight materials. Engineers of the Fraunhofer Institute for durability and system reliability in Darmstadt, now want to change way the components are design.

Eco-friendly Optical Measurement for Aircrafts in tests.

You could cut out a piece of the upper fuselage fairing of Barrot 70-seater ATR-72-600 and replaced it with a component made of CFRP. Its movements during different man-oeuvre precisely to document they outfitted the component with numerous sensors that measure the elongations, as by the changing pressure difference between inside and outside, as well as on the ground and at cruising altitude are.

Conventional measurement technology is too vague

Normal strain, that change their electrical resistance to deformation, the team led by the material scientist of Conchin Contell ASINs were inaccurate. They opted for an optical method. They glued fiber optic on the sites where they suspected large deformations in the millimeter range. They have the ability to change the frequency of light, which is initiated and reflected by a mirror at the end.

Conventional measurement technology is too vague
The medium-haul ATR 72-600 of the Italian manufacturer Alenia served the Fraunhofer engineers as test aircraft. An about 5 x 3 metre carbon fibre component was used for the flights. This area is one of the most polluting components during the flight. Photo: Alenia Aermacchi

From this, the deformation can be calculated to thousandths of a millimeter exactly. The test flights took place in the framework of a research initiative of the European Commission and the European aerospace industry.

Comparison of theory and practice.

“CFRP structures behave during a flight other than aluminum”, depicts Contell ASINs. Goal was to obtain metrics to compare them with the values, which are determined from calculations of deformation behavior.The measurement data were correlated still on board with the values provided by the black box, about speed, price changes, flight altitude and speed.

“The values were so exact that you can close the expansion signals to the flight profile,” says Oliver Black main technologist and team member.

The optical measurement technology can also be used to observe the functioning of the components during routine operation. Damage is unlike with metal parts hard to detect because they occur in the Interior. “The deformation behavior changes that may indicate damage. With such structural controls you could leave much longer parts in use”, says Contell ASINs.