3. Test Results
To find out if crack growth processes and patch delamination can be
differentiated on thermal images, at first solely the crack growth
process of metallic specimens without additional patches is monitored
using passive IrT. In addition, patched specimens are monitored from the
unpatched side to find out about possible differences caused by the
patch. At last, specimens with patched are monitored from the patched
side in order to monitor the overall damage progress.
3.1. Quasi-static Loading
Specimens without and with FRP patches are loaded quasi-statically and
damage behaviour is monitored using passive IrT. To measure temperature
differences, three measurement fields are defined on the specimen
surface. The first above the hole for the minimum temperature and the
second and third at the crack tips for the maximum temperature, see
Figure 5.