A constitutive model for semi-crystalline polymer deformation involving lamellar fragmentation

• Published in: Comptes rendus. Mecanique Vol. 338; no. 12; pp. 681 - 687
• Main Authors: Detrez, Fabrice, Cantournet, Sabine, Séguéla, Roland
• Format: Journal Article
• Language: English
• Published: Paris Elsevier SAS 01.12.2010; Elsevier
• Subjects: Cohesion; Constitutive relationships; Damage; Dommage; Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fragmentation; Fundamental areas of phenomenology (including applications); Génie des matériaux; Inelasticity (thermoplasticity, viscoplasticity...); Lamellar structure; Material engineering; Networks; Physics; Plastic deformation; Plasticity; Plasticité; Polybutene; Polybutène; Polymère semi-crystallin; Semi-crystalline polymer; Solid mechanics; Static elasticity (thermoelasticity...); Stress relaxation tests; Structural and continuum mechanics; Visco-elasticity; Visco-élasticité; Semi-crystalline polymer; Visco-élasticité; Plasticité; Polymère semi-crystallin; Fragmentation; Dommage; Polybutene; Génie des matériaux; Material engineering; Plasticity; Damage; Polybutène; Visco-elasticity; Constitutive equation; Viscoelasticity; Plastic flow; Crystalline polymer; Butylene polymer; Relaxation test; Semicrystalline polymer; Modeling; Tension test; Crystalline material; Inelasticity; Macromolecule; Damaging
• ISSN: 1631-0721; 1873-7234; 1873-7234
• DOI: 10.1016/j.crme.2010.10.008

The mechanism of lamellar fragmentation in the semi-crystalline polymers with spherulitic structure, is observed at the beginning of plastic flow. It causes significant damage. This elementary mechanism is considered here as a result of plastic deformation coupled with damage, in the framework of generalized standard materials. The simplicity and the efficiency of the proposed approach come from the fact that the semi-crystalline polymers are considered as a macromolecular network bridled by intra-lamellar cohesive forces. Tensile tests and relaxation tests demonstrate the usefulness of a damage–plasticity coupled model. Le mécanisme de fragmentation lamellaire, observé lors de la déformation des polymères semi-cristallins à structure sphérolitique, apparaît et endommage considérablement la microstructure, dès le début de l'écoulement plastique. Dans cette Note, consacrée à la modélisation du comportement de ces matériaux, le mécanisme élémentaire de fragmentation est pris en compte à l'aide d'un couplage plasticité/endommagement. Les développements présentés reposent sur la considération d'un réseau macromoléculaire bridé par les forces cohésives intra-lamellaire. Des essais de traction cyclique et de relaxation, sur le polybutène, valident l'intérêt de l'approche proposée.