An anisotropic nonlinear elasticity model for tearing of fibrous soft biomaterials

作者：Horgan Cornelius O^*; Smayda Michael G

来源：Mathematics and Mechanics of Solids, 2013, 18(6): 607-621.

DOI：10.1177/1081286513485762

• Constitutive models
• strain-stiffening
• anisotropic nonlinear elasticity
• soft fibrous biomaterials
• trousers test for tearing
• fracture toughness

The application of nonlinear elasticity concepts to the mechanical modeling of soft biomaterials is currently the subject of intense investigation. For fibrous soft biomaterials, some specific strain-energy density models for anisotropic hyperelastic materials have been proposed in the literature that are particularly useful as they reflect the typical J-shaped stress-stretch stiffening response due to collagen fibers that is observed experimentally. These models have the feature of incorporating the increased stiffness of the collagen fibers with deformation and involve a maximum fiber stretch (or locking stretch). Here we apply such models to the analysis of the fracture or tearing of fibrous soft biomaterials. Attention is focused on a particular fracture test namely the trousers test where two legs of a cut specimen are pulled horizontally apart out of the plane of the test piece. It is shown that, in general, the location of the cut in the specimen plays a key role in the fracture analysis, and that the effect of the cut position depends crucially on the degree of strain-stiffening. This dependence is characterized explicitly for the specific strain-stiffening constitutive models considered. The effects of anisotropy and strain-stiffening on the fracture toughness (resistance to tearing) are also examined.

• 出版日期2013-8