## 3 Analysis of Results
### Full Load Torsional Working Condition  
As can be seen from Figure 9, when the left front wheel is suspended, the left front area of the frame will be subjected to more gravity loads due to the constraint asymmetry. The maximum displacement in the frame occurs at the left front wheel position, and the trend of displacement changes gradually: it decreases from the left front wheel to the right rear wheel, and the maximum displacement is 18.18 mm. As can be seen from Figure 10a, the displacement in the front axle continuously increases from 4.87 mm at the right end of the axle (namely A-1) to 14.85 mm at the left end because the left front wheel is suspended. Compared with the front axle, the displacement change trend of the rear axle fluctuates less, and the displacement change in the rear axle increases from 1.32 mm at the right end of the axle to 2.94 mm at the maximum displacement, and then decreases to 2.93 mm at the left end of the axle. Figure 9: Displacement nephogram under torsional conditions. As can be seen from Figure 10b, the displacement changes in both the front and rear crossbeams show an increasing trend, with the right end of the crossbeam (namely C-1 and D-1) as the starting point. The displacement variation in the front crossbeam is larger than that in the rear crossbeam. The displacement change in the front crossrail increases from 3.05 mm to 13.25 mm, and the displacement change in the rear crossrail increases from 1.91 mm to 7.40 mm. As can be seen from Figure 10c, 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 longitudinal beam is consistent. The displacement change from the front of the longitudinal beam to the end of the longitudinal beam decreases first and then increases, and the displacement change in the left longitudinal beam is larger than that of the right beam; the displacement change in the left longitudinal beam is larger than that in the right crossbeam. This phenomenon is realized because the support state of the left front wheel changes, making the end of the longitudinal beam produce a slight displacement in the rear axle as the pivot point. The gravity of the vehicle equipment makes the displacement change in the frame when the left front wheel is suspended, and the high elasticity of the rubber material magnifies the displacement change to a certain extent. Combined with Figures 9 and 10, the maximum displacement in the left half of the frame under the torsion condition is 18.18 mm, while the displacement in the right half of the frame is less than 10 mm, and the displacement in the left side of the frame is larger than the displacement in the right side. It can be seen that the torsion condition is a typical dangerous condition in the process of vehicle driving, and so it should be avoided as much as possible in the process of driving. As can be seen from Figure 11, due to the asymmetry of the frame support caused by the overhang of the left front wheel, the maximum stress of the frame occurs at the front support plate of the left longitudinal beam, and the maximum stress is 352.68 MPa. The yield strength of the support plate is 785 MPa. It can be calculated that the safety factor of the frame under the full load torsion condition is 2.23. The strength of the frame meets the design requirements, and there is a certain design margin. Figure 10: Displacement curves of main components under torsion condition. (**a**) Axle displacement curve, (**b**) crossbeam displacement curve, and (**c**) longitudinal beam displacement curve. As can be seen from Figure 12a, the stresses in the front and rear axles have opposite trends. Taking the right end of the axle (namely A-1 and B-1) as the starting point, the stresses in the front axle showed a general trend of increasing first and then decreasing.