Eventos Anais de eventos
MECSOL 2022
8th International Symposium on Solid Mechanics
A thermodynamically consistent phase-field framework for structural damage in Polytetrafluoroethylene (PTFE) polymer
Submission Author:
Fabiano Fumes , SP , Brazil
Co-Authors:
Fabiano Fumes, Rodrigo Bresciani Canto, José Luiz Boldrini, Marco Bittencourt
Presenter: Fabiano Fumes
doi://10.26678/ABCM.MECSOL2022.MSL22-0120
Abstract
Considering the significant increasing of polymeric products and components in many applications, with different safety and quality requirements, the appropriate description of the mechanical behaviour of polymers is necessary for design purposes. Usually, polymers have quite different structural and thermal responses when compared to metals, which can impact their manufacturing process and usage conditions. Deformation in polymers is highly dependent on molecular structures and motion and relaxation mechanisms, which are highly influenced by temperature and mechanical load history. These features imply that some models can fit for specific classes of polymers and not for others, and also include several non-linearities, which turns out to be challenging for computational simulation. This work develops and simulates a phase field model for the polytetrafluorethylene (PTFE) polymer. Using finite element techniques in a one-dimensional domain, the stress-strain and fracture response of this model is compared to experimental result. The constitutive multimechanism model used in this work considers a non-linear elastoviscoplastic condition, originally used for amorphous polymers. Conceptually, the simulation is able to represent elastic molecular interactions and viscoplastic flow from polymer segments, like sliding and unkinking. Hardening at higher strains, due to polymer chain alignment, is also included. The fitting of material parameters from the rheological model is obtained by a genetic algorithm, in order to adjust curves from simulated models to stress-strain experiments available in literature. The result of stress-strain curve, followed by rupture is plotted in comparison with experimental results, presenting a reasonable fit.
Keywords
Phase-Field Model, Finite Element Method, Constitutive Models
