A new two-stage simulation approach for biaxial wheel fatigue test by introducing identified composite tire model

To improve accuracy and convergence of biaxial wheel fatigue simulation with coupled nonlinearity, we propose a two-stage approach based on a composite tire model. The tire model is calibrated through an identification procedure, wherein the actual tire stiffness characteristics are matched, effectively addressing the difficulty in lack of tire structure and materials information. Based on the identified tire model, restart analysis algorithm is employed to decouple the biaxial simulation into a two-stage analysis, where wheel deformability is sequentially considered. At the first stage, large deformation of the loaded tire is calculated by modeling the wheel as a rigid part. Then the deformation and stress states of tire are maintained at the second stage, and the wheel elasticity is recovered for stress calculation. Compared to a single-stage direct method, the proposed method significantly reduces computational costs, while exhibiting only a minor stress discrepancy on the wheel rim. Finally, experimental results show that the present method not only ensures high accuracy in predicting stresses of the wheel disc, but also effectively reduces errors on the wheel rim region. It is convinced that the proposed method provides an efficient and reliable means for the comprehensive evaluation of wheel strength in biaxial fatigue tests.