Research of Normal Contact Stiffness of Straddle-Type Monorail Tyres Based on Fractal Theory

The contact stiffness of on the rough surface of tread interaction (tire-track), a significant parameter for the tire-track contact surface, gives rise to direct influences on stiffness and noises of tyres. There is no sufficient theoretical support for the wheel face design due to lack of research on this parameter. To solve this problem, an innovative method based on the fractal theory and the Hertz contact theory is proposed to estimate tread interaction contact stiffness. The fractal theory model is established to research the influencing factors on normal contact stiffness on the tread surface. Finite element analysis and physical tests have been conducted to make comparisons about the model. According to research results, there is a non-linear relationship between the contact stiffness and the fractal dimension. The research provides theoretical basis for tyre dynamics of straddle-type monorail vehicles and design of the track contact dynamics.