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.