A numerical study of the influence of polydispersity on the behaviour until break of a reinforced hyperelastic material with a cohesive interface

Solid propellants manufacturers commonly monitor the granulometries of the explosive fillers they introduce in the material to pack high filler volume fraction and thus obtain satisfactory energetic performance. However, to our knowledge, the effect of a mix of small and large particles in the micrometric size range in filled elastomers has not yet been fully understood. This work aims at producing a better understanding of the underlying mechanisms that take place in a bidisperse filled elastomer composite under uniaxial loading by using finite element simulations. An original process for creating bidisperse microstructures is proposed and analyzed. The key role of the filler/matrix interface is emphasized through the use of a cohesive zone model. Plane-strain simulations in uniaxial tension of such cells with different fractions of large and small particles are performed.