PHASE FIELD APPROACH FOR SIMULATING FAILURE OF VISCOELASTIC ELASTOMERS

The description of a problem involving the existence of an interface or of a strong discontinuity requires to solve partial differential equations on a moving domain, whose evolution is also unknown, leading to severe difficulties, especially when the interface undergoes topological changes. The solution becomes even more complex when the whole problem domain changes, such as in mechanical problems involving large deformations. In this context, the phase-field approach allows to easily reformulate the problem through the use of a continuous field variable mimicking the real physical discontinuity. In the present paper we take advantage of such an approach for the description of damage and failure of highly deformable strain rate-dependent materials, such as the elastomeric ones. By harnessing a statistical physics-based micromechanical model of the polymer chains network characterized by the capability to reorganize the distribution of its chain lengths in time, the behavior of a rate-dependent polymer can be simulated. The adopted physics-based approach, upscaled at the continuum level and combined with a phase-field approach, allows us to describe the damage and fracture occurring in this class of materials in the large deformations regime. Some examples are provided to demonstrate the reliability of the proposed model.