Fig. 8: Maximum temperature difference ΔT for each heat pulse identified around the
hole
The maximum temperature variation \(T\) is plotted against the overall displacement and each detectable pulse is marked with the symbol . It has to be noted that with the used frame rate of \(f=200\) Hz these bands can only be seen on 1-3 images. Therefore, possibly not all bands were detected. The first detectable pulse appears at a displacement less than 2 mm with a maximum \(T=0.28\)K. With increasing displacement, the temperature difference increases up to \(T=3.12\)K. The intensity of the first and last detectable slip band, as shown in Fig. 6, visualizes the increase in temperature with a maximum temperature difference of \(T=0.28\)K for the first and \(T=3.12\)K for the last one. This means that with increasing test progress also visibility improves.
Further, for the tensile test two characteristic thermal events can be monitored, see Fig. 9.