A model for the contact behaviour of weakly orthotropic viscoelastic materials

• A contact model that considers viscoelastic and anisotropic behaviour was developed.
• The developed contact model uses one creep compliance function of the materials.
• The creep compliance to use is oriented along the indentation direction.
• A parameter study of the creep compliance on the real contact area was made.
• The time scale of the contact is relevant in the choice of contact model.

Fibre reinforced elastomers behave anisotropically as well as viscoelastically. Yang and Sun (1982) developed an elastic contact model for anisotropic materials which, in the present work, is extended to account for viscoelastic effects. The developed viscoelastic contact model uses the creep compliance function of the material in the direction of indentation. The results of the model agree with experimental results obtained on short fibre reinforced EPDM. Furthermore, a parameter study of the coefficients of the creep compliance function on the real contact area has been made. The results show that, at short time scales, the viscoelastic real area of contact can be significantly smaller than when assuming fully elastic behaviour. At long time scales the results of the viscoelastic contact model equal those of the elastic model of Yang and Sun.