Precision Vibration Measurement for Aerospace

During high-speed flight operations, an aircraft's wings are subjected to significant vibrations and deformations. Deformations can range from a few to several hundred millimeters, while vibrations can vary from nanometers to several hundred micrometers.

No conventional measuring device can cover such a measurement range of more than 160 dB in a single measurement. With the Optomet Nova Sense combined with the OptoGUI software, it is now possible to measure deformations and vibrations simultaneously with a dynamic range of more than 220 dB. The superior performance of the Optomet Nova Sense has been confirmed through measurements on wing models in a wind tunnel.

With the steady increase in air traffic, there is a growing need for fast and reliable inspection methods to verify the integrity of material connections. Although bonded joints are becoming more popular, riveted connections still make up the majority of connections in aircraft. Current standard inspection regulations require that rivets be visually inspected by certified personnel. These inspections are time-consuming, prone to errors, and early stages of failure are usually not detected.

Therefore, there is a strong interest in modern approaches that enable reliable and standardized inspection of rivet joints while reducing aircraft downtime.

Optomet Scanning Laser Doppler Vibrometers (SLDV) enable non-contact, reliable, and above all, objective early detection of loose rivets. When the corresponding aircraft part connected with rivets is excited over a wide frequency band, SLDVs can capture and analyze the complete vibration behavior of its surface within the analyzed frequency spectrum. Mapping the areas to be examined around the rivet joints with appropriate evaluations provides meaningful information about the condition of the rivets, such as the average amplitude of the vibrations, the coherence distribution of the measurement data, or the frequency response functions between different points on the surface.

A significant deviation of these values at narrowly confined locations compared to the rest of the surface allows for a direct assessment of whether there is a fatigued rivet joint at these points, even if the rivet joint is not visually detectable. The extent of the deviation also allows for an assessment of the fatigue level of the rivet joint, and thus a decision on whether the rivet should be replaced immediately or if the connection still has sufficient strength for continued operation and replacement can be carried out as part of a regularly scheduled maintenance plan.

In addition to analyzing aircraft structures, Optomet offers highly precise solutions for measuring the vibrations of individual turbine blades. These specialized applications help optimize turbine vibration behavior and detect potential resonance issues early. Detailed information can be found on our turbine analysis page.