Mechanism analysis on the increased stress softening of Mullins effect for rubber matrix composites

Abstract

The stress softening phenomenon of Mullins effect is studied by investigating mechanical properties of Fe (abbreviation of Iron) powder-modified rubber composites via experiments and numerical simulation methods. The distinct reinforcements of composites are found experimentally on the elastic modulus and the softened stress of Mullins effect. Then, a representative volume method: unit cell model method is selected to simulate the particle-reinforced composites, and investigate the intrinsic mechanism in the viewpoint of mechanics. It is found that due to the existence of rigid inclusion, the surrounding strain distribution field is changed and the continuous increasing stress characteristic of the matrix acts an important role in the mechanical reinforcement. The proposed mechanism based on it, can account for the increasing softened stress of Mullins effect for the composites. This finding can be also extended to other rigid particle-reinforced rubber composite, which is confirmed by numerically simulating.