Abstract

A “black box” model is described for simulating the dynamic forces transmitted to the vehicle hub by a tire running over an obstacle at high speeds. The tire is reduced to a damped one‐degree‐of‐freedom oscillating system. The five parameters required can be obtained from a test at a given speed. The model input is composed of a series of empirical relationships between the obstacle dimensions and the displacement of the oscillating system. These relationships can be derived from a small number of static tests or by means of static models of the tire itself. The model can constitute the first part of a broader model for description of the tire and vehicle suspension system, as well as indicating the influence of tire parameters on dynamic behavior at low and medium frequencies (0–150 Hz).

Abstract

The effect of tire load, speed, and cold inflation pressure on the rolling loss contribution of any tire region is determined by numerical calculations involving both laboratory measurements and thermal modeling techniques. Laboratory measurements include tire surface temperature distributions obtained from an infrared camera system; thermal modeling is based on finite‐difference procedures.

Results are presented in two formats: (1) plots of rolling loss distributions from bead to bead and (2) contributions of tread, shoulder, sidewall, and bead regions. The first format is a direct result of the thermal model; the second is derived from multiple‐regression operations. Both formats are given as functions of load, cold inflation pressure, and speed. Beahvior in the tread region is shown to be unique.

Abstract

A finite element which uses a unique approach to obtain three dimensional properties is described. The lamination model for the material uses a numerical integration technique to combine the properties of each laminate within the element. In‐plane and out‐of‐plane coupling are predicted. The ability to calculate interply shear strains is restricted only by the chosen shape function. Illustrations are given for inflated shape, interply shear strains, and cord loads in a typical bias mud and snow tire for light trucks.

Abstract

Accurate determination of stiffness properties of cord‐rubber composites is a key to successful finite element analysis of tires. The Halpin‐Tsai and similar equations which are used to determine stiffness properties of cord‐rubber single plies from the stiffness properties of cord and rubber do not provide adequate accuracy. Determination of these properties from strains directly measured by the Moire technique is more appropriate. In this paper the disadvantages of Halpin‐Tsai and similar equations as well as the advantages of the Moire technique for cord‐rubber composites are discussed. The stiffness properties obtained using the above different methods are compared. These stiffness properties are then used in the finite element analysis of a two‐ply cord‐rubber strip. The results of the finite element analyses are compared with experimental data.