MECHANICAL BEHAVIOR OF A SILICA FILLED RUBBER BASED ON A LARGE STRAIN VISCOELASTIC CONSTITUTIVE MODEL COUPLED WITH DAMAGE EVOLUTION

摘要

Silica filled rubbers exhibit complex mechanical behavior, including non-linear viscoelasticity and damage. Moreover, such a behavior involves finite strain analysis. This paper is concerned with the modeling of the mechanical behavior of a silica filled styrene butadiene rubber (SBR), used for shoe sole manufacturing. The steps which enable us to identify an hyperelastic-viscoelastic-damage constitutive equation are presented and discussed : microstructural examinations, mechanical testing, identification of the material constitutive parameters. The non linear elasticity is characterized by a Rivlin strain energy function. The softening is described with damage equation. The viscoelasticity equations are written using a Prony series based on hereditary integral concept. Finally, we present a validation based on finite element analysis of axisymmetrically notched rubber specimens tested under tension, compression and torsion. Numerical simulations of the notched specimens show good agreement with the experimental results.