Abstract

Tire vibrations supply energy for noise generation. Tread band features, such as grooves and blade cuts, affect noise signatures since they impart vibrations to a rolling tire. Finite element transient dynamics simulations have been performed with ABAQUS/Explicit on a rolling passenger tire to examine the vibrations induced by the entrance of tread pattern discontinuities into the contact patch. The loaded tire rolls on a 3.05 m (10 ft) diameter drum at terminal speeds of 4.3 km/h (2.7 mph) and 34.4 km/h (21.4 mph). Three models with augmented discontinuities in the circumferential ribs have been examined: 1) continuous (control); 2) angled lateral grooves; and 3) transverse grooves. They are ordered in increasing severity of rib discontinuity. The induced rolling vibrations are evaluated by identifying the ‘perturbed’ dynamic responses of (2) and (3) from (1). The results indicate that any discontinuity or abruptness in tread patterns can induce vibrations, which are similar in nature, for the two speeds studied. The higher rolling speed changes only the amplitudes, but not the frequencies of the induced oscillations at the free spindle. The ‘perturbed’ vibrations for both speeds manifest at the spindle as translational (vertical) and rotational (axial) oscillations of 29 and 44 Hz, respectively, for the tire studied.

Abstract

The bushing analogy tire (BAT) model has been shown to be capable of modeling tire dynamics in vehicle dynamic simulations. In a recent paper, the tire and vehicle data have been used to demonstrate that the BAT model yields reasonable predictions of the vehicle vertical suspension dynamic responses up to the tire 2nd vertical mode (∼90 Hz). This paper studies the modeling of the tire dynamics in the lateral direction as the next step toward completion of the BAT model as a consistent 3‐dimensional tire dynamics model.

Finite element (FE) analysis is an advanced analytical method for engineering analysis and has been accepted as the standard analytical tool for tires in the automotive industry. The tire data generated with FE models are also repeatable, without the data noise contained in physically measured laboratory tire data. FE models are also ideal for tire modeling studies because they enable the analysts to precisely control the modeling parameters. A tire FE model is, therefore, used here to generate the needed tire data, including mass, static forces and dynamic vibration modes for BAT model characterization.

The BAT model parameters, including the tire lateral stiffnesses and the tire/wheel mass and inertia, are extracted from the FE analysis results. The analytically predicted lateral vibration modal frequencies of the BAT model are then compared with the corresponding lateral vibration modes of the same FE model. It is shown that the resulting BAT model is a good approximation for the FE model in the lateral direction up to the third lateral (including rotational) vibration mode (∼70 Hz).

Abstract

When a vehicle travels over a large obstacle at a significant speed, dynamic loads are created that are severe enough to cause damage to its components. Prediction of these impact loads early in the design can greatly aid the vehicle development process. Thus, automobile manufactures have devoted considerable effort developing computer models to simulate durability events. An important part of any durability simulation is the tire model. This paper focuses on the problem of efficiently predicting dynamic loads that occur when an all terrain vehicle (ATV) impacts obstacle impact. An ATV simulation model that uses an efficient and simple tire model to represent the enveloping behavior and dynamic response was developed with the AUTOSIM multibody dynamics program. This program, using Kane's Method and symbolic algebra to automatically generate fully parametric simulations that are both efficient and easy to use, was used to model both the tire and ATV rigid body dynamics. This paper describes the combined ATV multi‐body vehicle dynamics and tire simulation. To demonstrate the effectiveness of tire simulation, results from the efficient tire model isolated from the vehicle are compared to output from a nonlinear finite element model. Also, the paper compares results from the full vehicle ATV simulation and a field test.