On Micromechanically‐Based Approaches to Failure in Polymers

Abstract

AbstractRubbery polymers comprise of three‐dimensional network structures, formed by flexible and mobile chains. They exhibit highly non‐linear ground state elastic combined with rate‐dependent inelastic material response. The key challenge in the micromechanically‐based modeling of polymer materials is the construction of micro‐macro transition that provides a bridge between microscopic kinematic variables of a single chain and macroscopic deformation measures of a continuum. The fracture toughness of rubbery polymers shows distinct rate dependency which can be identified through tearing tests. In this contribution, an overview on the micromechanical‐motivated modeling of polymeric materials will be given and different micromechanically‐based approaches to the modeling of rubbery polymers will be discussed. The novel aspect of the contribution is the incorporation of micromechanically‐motivated crack phase field model for the description of rate‐dependent fracture process in rubbery polymers. To do so, the viscoelastic spectrum of rubber network is idealized by a number of Maxwell branches superimposed to a ground‐state elastic spring representing the crosslinked network. The core of the ansatz is the incorporation of rupture of the superimposed network of dangling chains to the fracture process at different loading rates. We demonstrate the modeling capability of the proposed ansatz by means of representative numerical examples. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)