1. Deformation of spherulitic semi-crystalline polymers: phase field – mechanic coupling
- Author
-
Marc Cornu, Julien Boisse, Stéphane André, Laboratoire Énergies et Mécanique Théorique et Appliquée (LEMTA ), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
DLR model ,phase-field ,FFT code ,[SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph] ,Semi-crystalline polymers ,[SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph] ,visco-elastic behaviour ,[SPI.MECA.MSMECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Materials and structures in mechanics [physics.class-ph] ,[SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph] ,Spherulites ,[SPI.MECA.GEME]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanical engineering [physics.class-ph] ,[SPI.MAT]Engineering Sciences [physics]/Materials - Abstract
International audience; Semi-cristalline poymers (SCPs) such as High-Density-Poly-Ethylenes (HDPE) present a spherulitic microstructure. During mechanical loading micro-mechanisms of deformation in spherulites and their effect on the macroscopic response have to be clarified. We intend to use the AMITEX code [1] developed at CEA Saclay, firstly to solve the local mechanical equations on such a complex microstructure, and secondly, to couple it with a modelling approach of phase transformation type to explore the thereby opened simulation paths allowing for a better understanding of the damaging processes which explain the macroscale behaviour.The AMITEX code is based on an FFT method [2] and takes into account behaviour laws in UMAT format. To describe mechanical behaviour of crystal-amorphous two-phase spherulite structure we created a UMAT with a transversal isotropic law based on a DLR model [3]. This model allows predicting the local and overall behaviour between amorphous isotropic viscoelastic regions and orthotropic elastic crystallites accounting for their radial arrangement from spherulites centers. A phase field model was developed in AMTEX source code to describe phase changes in crystal-amorphous two-phase arrangements during loading. First computations of behaviour using the mechanical model coupled with the phase field method reveal a deterioration of crystal phases and crystal/amorphous interactions occurring during strain which can now beinvestigated more deeply with respect to the model parameters.
- Published
- 2021