Accounting the differential swelling in multiphysics moisture diffusion models

International audienceThe purpose of this paper is to take into account the deri vative by moisture content of polymer volume in order to establish a diffusion law within the so-called “thermodynamical approach” for a polymer material which experiences a hygro-mechanical load. In this study, the specific case corresponding to the existence of unsymmetrical hygroscopic boundary conditions was inv estigated

Coupling Moisture Diffusion and Internal Mechanical States in Polymers - A Thermodynamical Approach

International audienceA thermodynamical approach, based on the definition of the chemical potential of water, is used in order to establish a model coupling the diffusion of moisture to the mechanical behaviour of a polymer. The model takes into account the evolution, occurring during the diffusion process, of both the density of the polymer and its maximum moisture absorption capacity. The approach developed is applied to symmetric loading cases, in terms of relative humidity and external pressure. The model, established in the present work, provides the water content profiles through the thickness of the polymer throughout the transient phase of the diffusion process. The numerical results obtained show the significant effect of an external pressure on the kinetics of moisture diffusion in polymers

Une approche thermodynamique pour la modélisation multi-physique du comportement hygro-mécanique couplé des polymères

NANTES-BU Sciences (441092104) / SudocSudocFranceF

Durabilité des matériaux composites sous sollicitations hygrothermomécaniques

International audienceThe scope of the paper is to present the key points to be addressed in a durability study in the case composite materials in hygrothermomechanical environments. The experimental aging tests allowing the identificat ion of the diffusive behavior are presented. The induced effects on the mechanical behavior and the hygrothermomechanical coupling phenomenon are also examined.L’objectif de cet article est de présenter les points-clés d’une étude de durabilité pour des matériaux composites soumis à un environnement hygrothermomécanique. La démarche permettant de réaliser des essais de vieillissement afin d’identifier le comportement diffusif est présentée. Les effets induits sur le comportement mécanique et les phénomènes de couplages hygrothermomécaniques sont ensuite examinés