Modeling the mechanical behaviors of multiple network elastomers

Abstract

Compared with traditional single network elastomers, multiple network elastomers (MNEs) can achieve high stiffness and toughness. MNEs can be assumed as elastomer composites, where the first network elastomer serves as fillers and the other networks are assumed as matrix. Thus, similar to nanoparticle filled rubbers, MNEs also exhibit the Mullins effect. In addition, the mechanical response of MNEs shows significant dependence on the prestretching ratio of the filler network. In this work, a constitutive model is developed to describe the complex mechanical behaviors of MNEs. For a single chain, the Langevin statistics has been modified to incorporate the contribution of bond deformation. The polydisperse network of the filler network is progressively damaged with deformation, which is the underlying mechanism for the Mullins effect. Through incorporation the effect of prestretch caused by the matrix, the model also fully captures the stress–strain response of MNEs with varied stretching ratios of the filler network, which is beyond the ability of the classic damage models based on the Langevin statistics.