On Fracture Modeling and Characterization of Elastomeric Materials and Composites for Design Applications

Existing approaches of fracture analysis of elastomeric materials are primarily based on classical Griffith’s theory of crack growth. There are numerous experimental, analytical and computational studies covering applications of these approaches for a wide range of different polymeric materials, loading and environmental conditions, methods of testing and modeling, etc. However, these results are usually based on certain assumptions regarding original cracks (their sizes, shapes, locations, etc.), i.e., damage initiation is considered as the input of such analysis rather than the output. To avoid this challenge, an advanced approach predicting both a) damage initiation and b) damage growth is considered in this study for analysis of hyper-elastic materials such as rubber and elastomeric composites. The approach is specifically proposed for FEA implementation and is based on so-called cohesive elements. Such elements mimic contact between individual elements and account for both material strength and toughness properties. Implementation of the approach for hyper-elastic deformation is considered in detail. Several examples illustrate computational efficiency and benefits of the approach for design applications. Challenges and opportunities of material characterization for the approach are discussed as well.