Further investigation on improved viscoelastic contact force model extended based on hertz's law in multibody system

Abstract

• The shortcoming of the existing improved contact stiffness coefficients is analyzed systematically. • A new contact force model suited for the internal contact between the cylindrical bodies is proposed. • The other contact force model suited for the external contact between the cylindrical bodies is proposed. • The correctness of the external contact force model is validated by the bouncing example, the reasonability of the internal contact force model is proved by the experimental data. Since the Hertzian contact stiffness coefficient is closely related to the power exponent, the modification of the Hertzian contact stiffness coefficient leads to some problems: (i) the power exponent must be changed with the improved contact stiffness coefficient, otherwise, the unit of the contact force is not newton; (ii) since the power exponent is one of the factors to determine the magnitude of the contact force, the inappropriate power exponent makes the multibody system hard to convergence or lose physical meaning. The main goal of this investigation is to reveal the shortcoming of the improved contact stiffness coefficient, and develop two different contact force models suited for the internal and external contact form associated with the hysteresis damping factor from Lankarani-Nikravesh contact force model (L-N model). The effectiveness of the external contact force model is validated by the bouncing example. The correctness of the internal contact force model used in the multibody system with a clearance revolute joint is validated by the experimental data.