ABSTRACT
Mullins effect in the mechanical behaviour of filled rubber materials is connected with a distinct strain-induced anisotropy. Even the simple shear deformation mode is suitable to detect the directional sensitivity of Mullins effect, provided that a loading sequence according to Dr. Alan Muhr is carried out. To understand filled rubber behaviour and to predict it with the help of constitutive models, especially in the case of inhomogeneous loading, it is essential, to understand Mullins effect. Because this effect denotes substantially irreversible softening, and thus, is an inelastic effect, the development of suitable models and the implementation of those models into the finite element method are complicated. The distinct differences between the simulation results using an isotropic softening formulation on the one hand and the real material behaviour on the other hand show, that in many technically relevant situations anisotropic softening have to be considered within the constitutive model to obtain reliable simulation results.
