Working area
The ultrasonic echo method (frequency range 50 to 200 kHz) has been developed for investigation of the inner structure of construction elements. The aim is to extend the use of these methods in on-site testing and to improve their reliability. The testing issues mainly relate to reinforced concrete. Some examples are: the thickness measurement and geometry of concrete elements, the identification and locating of debonded areas in layered systems and of injection faults, as well as the characterisation of cracks. For high resolution experiments the data is obtained by means of transducer arrays (see figure) or a laser scanning doppler vibrometer.
Array of ten low frequency transducers
A three-dimensional reconstruction of the backscatter from the volume of the specimen is created, in co-operation with partners (Fraunhofer IZFP, Saarbrücken; University of Kassel). This enables, for example, the acoustic imaging of tendon ducts or the analysis of defects (3D-SAFT: Synthetic aperture focusing technique).
Service
Division 8.2
Dr. rer. nat.