Όνομα Συνεδρίου:10th International Conference of the Slovenian Society for Non-Destructive Testing
Marble beams were subjected to gradually increasing three-point bending from low loading levels
up to levels that significant damage was observed. After each loading step the permittivity was
measured at three characteristic locations: the tensional, middle and compressional zone of each
sample. The permittivity measurements were conducted in the frequency range from 1kHz to 1MHz.
The permittivity values were compared for the three locations at the frequency of 10kHz. The
experimental results indicate that the permittivity values decrease after each loading at the three
selected locations. More specifically, the permittivity variation is more intense at the tensional zone
(due to intense cracking processes) than the compressional zone, while the middle zone exhibits the
lowest variation in permittivity. Thus, the damage magnitude of each sample can be estimated by
permittivity measurements before the fracture of the sample.