4.2.1. Tensile Stress Analysis

The surface of the asphalt pavement undergoes deflection changes under the coupled dynamic load of the vehicle. At the same time, the road structure layer also undergoes bending and tensile stress. Under repeated vehicle loads, this bending and tensile stress will cause bending and tensile fatigue damage to the asphalt road structure.

Figure 10 shows the time–history curve of the maximum tensile stress at each node of each structural layer on the road. It can be seen from the figure that the tensile stress on the road is sometimes positive and sometimes negative, but it is the maximum at the road surface course and the base course.

Figure 11 shows the horizontal stress nephogram at the position of the maximum tensile stress at each node of the road structure layer. From this figure, it can be seen that the maximum tensile stress mainly occurs in the road surface course at the vehicle load and the combination part of the road surface course, bed course, and subgrade at the load, while the combination part of the road surface layer and the cushion is the largest. This shows that each structural layer of the road is relatively easy to damage in these parts. For the tensile stress of the road structure, it is easy to cause the cracking of road pavement on the surface course. However, there is a large tensile stress at the joint between the structural layers, which will increase the wear between the structural layers and directly lead to the damage of the road.
