A new elastoviscoplastic model based on the Herschel–Bulkley viscoplastic model

✍ Scribed by Pierre Saramito

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 623 KB
• Volume: 158
• Category: Article
• ISSN: 0377-0257
• DOI: 10.1016/j.jnnfm.2008.12.001

✦ Synopsis

The aim of this paper is to introduce a new three-dimensional elastoviscoplastic model that combines both the Oldroyd viscoelastic model and the Herschel-Bulkley viscoplastic model with a power-law index n > 0. The present model is derived to satisfy the second law of thermodynamics. Various fluids of practical interest, such as liquid foams, droplet emulsions or blood, present such elastoviscoplastic behavior: at low stress, the material behaves as a viscoelastic solid, whereas at stresses above a yield stress, the material behaves as a fluid. When n = 1, a recently introduced elastoviscoplastic model proposed by the author is obtained. When 0 < n < 1, then the plasticity criteria becomes smooth, the elongational viscosity is always well defined and the shear viscosity shows a shear thinning behavior. This is a major improvement to the previous elastoviscoplastic model. Finally, when n > 1, the material exhibits the unusual shear thickening behavior.