A computer program is developed to calculate the internal temperature distribution in a rolling tire. The geometry of the tire cross section is transformed to simple computational domains by using a boundary-fitted coordinate transformation method. A heat transfer equation in the tire is also transformed to be calculated in the computational domain. Heat generation rates are estimated from load, speed, contained air pressure, and a static stress and strain analysis. An unsteady two-dimensional heat conduction equation is solved with heat convection and radiation boundary conditions. External surface temperature distributions are measured by an infrared camera system and the temperature of the contained air is measured by a thermocouple. The conductivities of various materials in the tire and various heat transfer coefficients along the tire boundary are given in an input file. Some internal temperatures measured by buried thermocouples in the actual tire are compared with the calculated temperatures.

The pneumatic tire has a very complicated geometrical shape and is subjected to large deformations. Measurement of the stress and strain distributions in the tire is difficult. In this study, the reflective photoelastic method was used to measure the distributions of stress and strain on the surface of the tire sidewall. It was assumed that the pneumatic tire takes the shape of a toroidal shell of revolution and that the strain of the photoelastic coating is the same as that of the tire surface. The force equilibrium equations for shell elements were derived and the principal stresses were extracted by the shear difference method. The normal stresses and the shear stresses were obtained by numerically integrating the equilibrium equations. The initial values for the integration were determined using the oblique incidence method.