New method for simulation of Mullins effect using finite element method

Especially filled rubberlike materials exhibit distinct stress-softening phenomena under cyclic loading commonly known as the Mullins effect. This effect is often explained by chain breakage inside the material which is simulated in the present contribution by an innovative approach. Special finite element unit cells are defined consisting of one tetrahedral element and six truss elements. Putting arbitrary configurations of such unit cells randomly together allows us to simulate complex structures of unfilled elastomers. Filler particles are added by replacing a certain part of the tetrahedrons by linear-elastic material (the filler material). In this way, the increase in stiffness and strength of the composite material is accounted for. Based on comparisons with experimental results, the breakage and reformation of polymer chains is simulated. A satisfactory correlation is obtained between the numerical results and experimental data, also for the large strain regime.