finite element analysis and footprint determination of a bias truck tire under vertical static load using global/local method

afinite element model of a bias truck tire under static vertical load using a global/local technique is designed in two parts. in the first part a previously created model for radial tires is developed to take the constructional variables of bias tires into account. it is shown that the technique can successfully be used for bias tires. the main challenge here is the selection of the initial layout of the tire, which due to the use of nylon fibers in bias tires undergo considerable variation in shapes on being released from mold. therefore, the selection of the tire lay out in the mold as the initial starting point for finite element calculations leads to significant errors in the final results. in the second part, a highly refined mesh has been created from contacting region of the tire tread pattern as a local model. this model is analyzed using the results of the first (global) model as the boundary condition. it is also shown that the developed method is capable of precisely predicting the geometry of the footprint area without any extra computational cost and efforts needed in finite element calculations of full tire models.