Abstract

The hysteretic behavior of tire rubber compounds was investigated by tension/compression tests at different strains and strain rates, dynamic tests with varying frequencies and amplitudes, and tests with small cycle loading and unloading. According to these effects, a material model was developed that considers the complex frequency dependent (viscoelastic) as well as the rate independent (elastoplastic) inelastic behavior of filled rubber. This model combines different rheological elements representing viscous and plastic effects. The approach is valid for large strains.

The hysteretic model has been implemented in an in‐house FE code to analyze tire behavior assuming a constant driving velocity. The numerical algorithm is robust and shows excellent convergence, making it suitable even for large tire models. In computations for rolling tires, the consideration of the hysteresis yields a direct calculation of rolling resistance and energy dissipation, thus the new material law should prove useful in simulations of wear and durability.

Abstract

A complete finite element tire model was developed for the purposes of vehicle dynamics analyses and full vehicle finite element model real time proving ground simulations. The tire model was validated through simulations of some of the very important global, static and dynamic mechanical properties such as the tire radial and lateral stiffnesses, free‐drop test, and low‐speed rolling cornering stiffness. The three‐dimensional free vibration and harmonic/randomly forced vibrations with ground contact of the tire model were studied here. One of the main purposes for the present study is to provide a new approach toward tire and vehicle NVH studies. All the analyses were nonconventional in the sense that, instead of NASTRAN‐type modal analysis, the explicit nonlinear dynamic finite element code LS/DYNA3D was used to conduct all the analyses in the time domain, and the vibration modes were decomposed via fast fourier transformation.

Abstract

Vibration transmission through tires due to forces generated by the road‐tire interaction during rolling over a rough road surface is an important source of noise in the vehicle interior over a wide frequency range. Vibration transmission along the tire tread and across the sidewalls to the rim was measured by striking the tread with an impact hammer in generating transfer functions for comparison with results from an SEA model of the wheel. The effects of tire and rim resonances are noted. Transfer functions to acoustic levels in the tire cavity were also measured.

Abstract

Tire properties are some of the most important factors causing vehicle drift. In this paper, the influences of wheel alignment and tire properties on vehicle drift are discussed. The relationship between the wheel alignment of a vehicle and vehicle drift are examined. Also analyzed is the relationship between vehicle drift and front tire torque by using a four‐wheel model while considering tire characteristics. The calculated front tire torque is compared with vehicle drift.