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.