## 3 Analysis of Results
### Emergency Turning Conditions  
As can be seen from Figure 13, the maximum displacement in the turning condition occurs at the wheel, and the maximum displacement is 2.61 mm. When the wheels are not considered, the displacement change in the frame becomes larger from both ends to the middle in the state of turning left. The maximum displacement occurs at the middle of the longitudinal beam on the right side of the frame, and the maximum displacement in the middle section of the frame is 2.20 mm. At the same time, the maximum displacement area of the middle section of the frame tends to increase from the left side to the right side, which is consistent with the actual situation of turning conditions. Figure 14a shows that the displacement in the front axle rises gradually from 1.61 mm at the right end of the axle (A-1) to the maximum displacement of 1.89 mm in the middle of the axle; after that, the displacement gradually decreases as the distance increases, and the displacement in the right end of the axle is slightly larger than the displacement in the left end, which is 1.59 mm. The displacement trend of the rear axle is consistent with that of the front axle. Compared with the front axle, the displacement in the right end of the rear  
Figure 13: Displacement nephogram under turning condition. axle was 1.62 mm, the maximum displacement was 1.91 mm, and the displacement in the left end was 1.60 mm. As can be seen from Figure 14b, the displacement curves of the front and rear crossbeams show a continuous decrease when the right end of the crossbeams (namely C-1 and D-1) is taken as the starting point. The displacement in the front and rear crossbeams decreased from 2.13 mm and 2.13 mm, respectively, to 2.07 mm and 2.08 mm. The displacement in the right side of the front and rear crossbeams is larger than that of the left side, which is mainly caused by the centripetal acceleration during the turning process. As can be seen from Figure 14c, taking the front end of the longeron (namely E-1 and F-1) as the starting point, the displacement variation trend of the left and right longerons is consistent. The displacement change from the front end of the longitudinal beam to the rear end of the longitudinal beam shows the phenomenon of first increasing and then decreasing, and the overall displacement in the right longitudinal beam is slightly larger than the overall displacement in the left longitudinal beam. Among them, the front end displacements in the left and right longitudinal beams are 1.63 mm and 1.64 mm, and the maximum displacements occur in the middle of the longitudinal beams. The maximum displacement in the left and right longitudinal beams is 2.18 mm and 2.20 mm, and the displacements in the right end are 1.66 mm and 1.67 mm, respectively. The overall displacement in the frame and the displacement in each key component are small in the turning condition. As can be seen from Figure 15, the maximum stress location of the frame under the turning condition occurs on the axle bracket at the connection between the base of the right longitudinal beam and the front axle, and the maximum stress is 79.718 MPa. The yield strength of the axle support is 785 MPa. It can be calculated that the safety factor of the frame under the emergency turning condition is 9.85, and so the strength of the frame meets the design requirements. Figure 14: Displacement curves of main components under turning condition. (**a**) Axle displacement curve, (**b**) crossbeam displacement curve, and (**c**) longitudinal beam displacement curve. As can be seen from Figure 16a, the stresses on the front and rear axles change from the ends of the axles to the middle with the trend of first increasing and then decreasing, and the stresses increase rapidly when approaching the axle supports, which means that the maximum stresses on the midline of the upper surface of the front and rear axles are located at \(l\) = 297 mm and \(l\) = 971 mm. The maximum stress on the front axle is 57.62 MPa, and the maximum stress on the rear axle is 58.25 MPa.