A novel constitutive model of carbon black rubber for the numerical analysis of press-fitting of rubber bushing

The mechanical constitutive model of carbon black rubber is fundamental to the accurate Finite Element Analysis (FEA) of the press-fitting process of the rubber bushing. However, the deformation behaviour of carbon black rubber in its press-fitting process is highly complex, which consists of large and multiple deformation modes. In this study, a new constitutive model of carbon black rubber is proposed by reducing the number of undetermined coefficients of the classic Ogden model. This new model can cover three deformation modes, i.e., the uniaxial extension, equibiaxial extension, and planar extension. Correspondingly, three kinds of deformation tests were conducted to obtain the strain–stress data of carbon black rubber. Curve fitting results demonstrate that the proposed new constitutive model can globally fit with the strain–stress data well for all the three deformation modes. In contrast, the conventional reduced polynomial model can only have acceptable fitting accuracy for local and small amounts of data. Finally, the FEA of press-fitting process of rubber bushing with the proposed constitutive model was performed by using user-defined material subroutines in Abaqus/Explicit (VUMAT). The simulated results of the overflow of rubber bushing agree well with the experimental results, further verifying the efficacy of the proposed constitutive model of carbon black rubber.