Air-coupled ultrasound

Radalytica a.s., in cooperation with SONOTEC GmbH, integrates air-coupled ultrasonic probes. They are particularly effective for detecting delaminations in composite materials that are virtually invisible by X-rays. Air-coupled ultrasound will also find further use in material, aviation and other research fields.
Different imaging methods have different uses depending on the required application. In many cases, it is appropriate to use more than one method at a time to get a better overview of the sample.
A good example is a damaged composite wing of an aircraft after hitting a foreign object. The X-ray image reveals the structure of the composite and its possible damage by fine cracks at the point of impact. However, delamination in the surrounding area cannot be detected by X-ray. Ultrasound is nevertheless suitable for the detection of delamination, but it does not allow high-resolution imaging of fine cracks. The solution is a combination of these methods.

Honeycomb sandwich panel with simulated honeycomb-to-skin defect.

Both scans show the artificial circular inserts simulating disconnection of the honeycomb from the skin. The X-ray can detect all insert sizes. UT detects inserts at level ~4 cells.

X-ray comparison with Ultrasound (UT) on sample CRFP

In the example above, both UT and X-Ray detect the damaged area, UT detects delamination, but only the combination of methods shows all available data – delaminations, cracks even fibre bundles.