## 5 Results  
For the purposes of the analysis of the DIC results, an independent definition of the gondola markings was prepared (Figure 3a), in which: E1--ring A, E2--ring B, P--floor/bottom frame, S--ceiling/upper frame. Longitudinal dimensions were marked with the letter L, transverse dimensions with the letter B, and dimensions in the vertical  
Figure 11: Screenshot from the TRITOP Professional program. The image shows a cloud of measurement and reference points along with the adopted coordinate system.  
Figure 12: Displacements of measurement points.  
direction with the letter H. For example, the designation E1_B describes the change in the width of ring A.  
Based on the conducted tests, a set of results was prepared to show the change in the characteristic dimensions of the gondola in the directions mentioned above (deformation of the rings, distances between them, distances between the upper and bottom frames, etc.). The obtained results are summarized in Table 2. For the purposes of a more accurate interpretation of the results, a graph was prepared in Figure 13, showing the change of individual distances (displacements) during subsequent inspections with the DIC system.  
Based on the measurements, it can be concluded that there was no permanent deformation of the structure. The obtained changes in the characteristic dimensions of the structure assume small values of the order of measurement uncertainty. No growing tendencies of these dimensions are observed. They have a variable character resulting from  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline  & & & & \multicolumn{6}{c}{**Measurement Number**} & \\  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** \\  & & & & & & & \(\Delta u\)**, mm** & & & & \\ \hline E1\_B & 0 & 0.0597 & 0.0490 & \(-\)0.1196 & 0.3406 & 0.3121 & 0.1049 & 0.1890 & 0.4372 & 0.1845 & \(-\)0.1933 \\ E1\_H & 0 & 0.5389 & 0.1003 & 0.2690 & 0.6537 & 0.5011 & 0.4095 & 0.5292 & - & 0.5546 & 0.5125 \\ E2\_B & 0 & 0.0023 & \(-\)0.5304 & \(-\)0.5448 & 0.1273 & \(-\)0.0045 & \(-\)0.1817 & \(-\)0.0669 & 0.2411 & \(-\)0.2513 & \(-\)0.1993 \\ E2\_H & 0 & 0.7362 & 0.4008 & 0.4726 & 0.8139 & 0.6397 & 0.7383 & 0.6953 & 0.9075 & 0.7517 & 0.6875 \\ P\_B & 0 & 0.5713 & 0.6962 & 0.1860 & 0.3598 & 0.0465 & 0.2880 & 0.2764 & 0.2102 & 0.0968 & 0.1373 \\ P\_L & 0 & \(-\)0.7276 & \(-\)1.1064 & \(-\)0.2631 & \(-\)0.5402 & \(-\)0.0079 & 0.0761 & \(-\)0.3646 & \(-\)0.5621 & \(-\)0.0036 & - \\ S\_B & 0 & 0.0664 & \(-\)0.0537 & \(-\)0.0380 & 0.0915 & 0.0318 & \(-\)0.0404 & 0.0392 & 0.1738 & 0.0220 & 0.0268 \\ S\_L & 0 & \(-\)0.1037 & \(-\)0.0471 & \(-\)0.1290 & 0.1188 & 0.0136 & \(-\)0.0312 & 0.1181 & 0.2630 & 0.2198 & - \\ \hline \end{tabular}
\end{table}
Table 2: Changes in the characteristic dimensions (deformation) of the gondola in successive measurements.  
Figure 13: Measured deformation of the gondola during next examines.  
the residual load during the measurement. This, in turn, results from the fact that during the measurements the loading system was not disconnected from the test object.  
Conducted in parallel to the DIC, research using laser sensors allowed to determine the level of displacement of the bottom and upper frame of the tested gondola. The results are presented in Figure 14. The difference in levels of about 1.5 mm is the actual spreading of the gondola elements--stretching of the \"A\" and \"B\" rings. The slight phase shift shows the delay in the appearance of the displacements between the frames.  
After the fatigue tests are completed, before dismantling the gondola from the strength cage, an inspection should be carried out by the Certification Laboratory (in the case of the test facility in question--the TDT Laboratory with its registered office in Krakow).