Ultrasonic phased-array test pliers

Until now, there has been no inline-capable ultrasound-based testing device for folded adhesive joints available; such joints are used mostly in machine engineering and the automotive industry. For this reason the engineers at Fraunhofer IKTS have developed a testing system that uses ultrasound to measure the distribution of adhesive and detect the existence of voids in the fold.

They produced three linear phased-array probes integrated in a pair of special test pliers. By mechanically opening and closing two parts, the fold can be positioned optimally between the three probes on sides a, b and c (see figure). An integrated water cycle ensures good acoustic coupling to the metal parts.

The test plier has already been passed to industrial application in combination with the IKTS’ PCUS^®-pro array frontend and a customized PCUS^®-pro lab software. The developed principles for the probes excitation as well as the implemented algorithms for the signal analysis are based on simulation and modeling.