An anisotropic hyperelastic constitutive model with shear interaction for cord–rubber composites

An anisotropic hyperelastic constitutive model for tire cord/rubber composites is proposed. The strain energy of the cord/rubber composites material is nominally decomposed into four parts, representing the strain energy from rubber, cords, shear interaction and normal interaction between rubber and cords, respectively, which makes a separate investigation of contribution of each part of strain energy available. The geometric relationship between the cord and rubber, in the original and current configuration, is analyzed in determining the characteristics of each strain energy part. By including the so called shear interaction and normal interaction strain energy which cannot be neglected under particular deformation conditions, the accuracy of the model is greatly improved. A simple approach for fitting the model parameters is given. Experimental data from literature is used to identify these material parameters in the constitutive model for a specific cord/rubber composite. The developed constitutive model is validated through a comparison between experimental data and predicted results under certain deformation modes. Very good agreement is obtained.