## 5 Verification of Simulation Results  
### Verification of the Fatigue Test  
Combined with the finite element simulation, the fatigue test was carried out on the fatigue test platform of an ACSR. Figure 7 shows the three-dimensional design of the fatigue test platform of an ACSR. The initial adjustment device was fixed to the tension clamp at the end of the ACSR, and the pretension and other parameters of the ACSR could be adjusted according to the working conditions on site. The axial adjustment device can exert axial tension on the ACSR. The device for transverse motion acted directly on the ACSR, causing it to move transversely, and the amplitude of the conductor swing can be adjusted. A steel-cored aluminum strand of LGJ-400/50 (Dazheng electric wire Corp, cangzhou, Hebei, China) was pressed in the tension clamp and assembled on the fatigue test platform of the ACSR. A displacement of 89 mm (Y\({}_{\text{b}}\)) at the outlet of the tension clamp was measured using a dial indicator. The Y\({}_{\text{b}}\) simulated by the finite element method under the level-7 wind load was set to the maximum displacement (Y\({}_{\text{b}}\)) of 89 mm at the outlet of the tension clamp during the fatigue test, and a cyclic fatigue test was then conducted. Three groups of experiments were conducted. Table 3 shows that the cyclic fatigue life of the conductor was between 150,000 and 300,000 times without or with very little tension. As shown in Figure 8a, there was an obvious stress concentration at the outlet of the tension clamp for the outermost conductor and the third layer of conductor. As shown in Figure 8b,c, \(\sigma_{\text{a}}\) of the third layer of the conductor (79.7 MPa) was greater than \(\sigma_{\text{a}}\) of the outermost conductor (71.4 MPa), which was very interesting. Under the guidance of the finite element results, when one strand of the outermost conductor broke during the fatigue test, the outermost conductor was cut off completely, as shown by arrow A in Figure 9. Interestingly, at this time, the third layer of conductor had almost broken, as shown by arrow B in Figure 9. This indicates that at the outlet of the tension clamp, the crack of the third layer of conductor occurred earlier than the outmost conductor, which shows the accuracy of local model simulation results. \begin{table}
\begin{tabular}{c c c} \hline
**Specimen** & **Y\({}_{\text{b}}\)** & **Cycles (Number of Times)** \\ \hline Specim A & 0.45 & 156,000 \\ Specim B & 0.45 & 290,000 \\ Specim C & 0.45 & 226,000 \\ \hline \end{tabular}
\end{table} 
Table 3: Results of fatigue tests. Figure 7: 3-D design drawing of the fatigue test platform of a steel-cored aluminum strand (ACSR). Figure 10a shows the macroscopic morphology of the fatigue fracture. As shown in Figure 10b, the fatigue band with the characteristics of bainite lines was observed. These fatigue bands were thick, short, deep, wide, and discontinuous, which obviously accorded with the characteristics of low cycle fatigue fracture bands. Therefore, under the level-7 wind load, the stress concentration of the third layer at the outlet of the tension clamp had yielded. To summarize, the results of the fatigue tests were in good agreement with the simulation results, which proved the accuracy of the local model simulation results. Figure 8: Stress distribution of local model at the outlet of the tension clamp: (**a**) the stress distribution of each layer, (**b**) the stress distribution of the third layer of the conductor, and (**c**) the stress distribution of the outmost conductor. Figure 10: (**a**) The macroscopic morphology of the fatigue fracture, and (**b**) morphology of the fatigue fracture. Figure 9: Fracture diagram of the third layer of conductor. As shown in Figure 11a, after cutting the outermost conductor, it was found that the third layer of the conductor has obvious wear on the surface at the outlet of the tension clamp.