New predictive model for the study of vertical forces (up to 250 Hz) induced on the tire hub by road irregularities

摘要

A physical model has been developed in order to study the forces induced on the tire by road irregularities. It works in a range of frequencies 0-250 Hz, i.e. up to frequencies that are felt by the passengers as noise and vibrations, but it can be easily improved to 400 Hz. The model can resolve road irregularities with wavelength greater than 5 cm (pavement megatexture). The parameters of this model have been identified by comparison with special virtual tests performed on a 3D finite element model of the tire, i.e. without using any experimental data. Once built, the model can be used to analyze the forces transmitted by the tire to the vehicle while passing over various pavement textures for testing both the tire-vehicle system and the pavement textures. Since the model doesn't require any experimental data, it can be used to predict the dynamical characteristics of tires which haven't been built yet, speeding up the optimization process of tires under development. Due to its characteristics, this model appears to be a powerful tool for a joint analysis of vehicle and tire, but it would require vehicle models with a similar frequency response range, currently not reported in literature. Comparisons with the results of indoor cleat tests and with measurements on a test car with an instrumented wheel hub have shown that the mathematical model reproduces with good accuracy the behavior of the tire in the frequency range of interest.