Dynamic Response Predictions of a Truck Tire Using Detailed Finite Element and Rigid Ring Models

A detailed nonlinear finite element (FE) model of a radial-ply truck tire has been developed using an explicit FE code, PAM-SHOCK. The tire model was constructed to its extreme complexity with three-dimensional solid, layered membrane, and beam elements. In addition to the tire model itself, a rim model was included and rotated with the tire with proper mass and rotational inertial effects. The predicted tire responses, such as vertical stiffness, cornering force, and aligning moment, correlated very well to physical measurements. For complete vehicle simulations, a faster and simplified tire model is required for efficient analysis through-put. The behavior of such a tire model can be verified and improved by comparing responses with the developed FE model. Moreover, the parameters needed for the simplified model can be determined by the developed model instead of having to rely on tire measurements. The in-plane sidewall transitional stiffness and damping constants of the FE tire model were determined by rotating the tire on a cleat-drum. The other constants, such as in-plane rotational stiffness and damping constants, were determined by applying and releasing a tangential force on the rigid tread band of the FE tire model. The tire axle, spindle, and reaction force histories at longitudinal and vertical directions were recorded. In addition, the FFT algorithm was applied to examine the transient response in frequency domain. The tire steering characteristics were also determined. These parameters were used as input for a simplified rigid ring tire model. This study will discuss the results obtained from both the developed tire and the rigid ring tire models while both models are rolling at 12 mph constant linear speed and loading range of 13,345 N (3,000 lbs) to 53,378 N (12,000 lbs). The dynamic responses for the developed FE tire model were compared with the dynamics predicted using the rigid ring model. The results will show a successful attempt to capture the transient response of a tire rolling over a complex road profile.