Finite element analysis of a tire using an equivalent cord model

• An accurate wire cord finite element model was developed.
• Two equivalent cord models were proposed.
• Global–local analyses were conducted to calculate the strains at the belt edge.
• The two equivalent cord models resulted in different shear strains.

In tires, cracks usually nucleate at the belt edge and grow along the belt–rubber interface. Therefore, to assess the durability of a tire a method of analysis that can accurately simulate the belt is needed. However, in previous studies, a belt cord model that could represent both tension and bending well was not used. Therefore, in this study, to simulate the behavior of the cords in the belt, a wire cord finite element model was developed to accurately model the geometry of cords, and the validity of the model was verified through comparisons of tensile and bending simulation results with test results. However, the configuration of the wire cord model was too complicated and involved too many elements to be used to model the whole tire. Therefore, two equivalent cord models capable of simulating the behavior of the wire cord model were proposed. One was a cord model with solid and truss elements, and the other was a cord model with solid elements that have bilinear material property. Global–local analyses were conducted using a solid element cord model, a rebar element cord model, and the equivalent cord models to obtain the strains at the belt edge. The comparison of the results demonstrated that more appropriate strains could be obtained using the equivalent cord models than the solid element cord model or the rebar element model.