‘Reconstructing babel’: Christian missions and knowledge production in the Middle East, nineteenth-twentieth century

FGW – Publications not associated with a particular research are

Viscoelasticity properties of biopolymer composite materials determined using finite element calculation and nanoindentation

International audienc

Caractérisation multiaxiale d'un PolyHydroxyAlcanoate et simulation avec un modèle de comportement HVH

National audienceL'étude porte sur la caractérisation des propriétés mécaniques d'un grade de PolyHydroxyAlcanoate (PHA) sous chargements multi-axiaux. Un montage expérimental original a été développé permettant la réalisation d'essais en température avec une unique éprouvette en forme de tube cylindrique, pouvant être sollicitée successivement et/ou simultanément en traction-compression-torsion. L'objectif est de pouvoir effectuer des chemins complexes permettant d'explorer tout le plan déviatoire de déformation. De nombreux essais ont été effectués permettant l'identification des paramètres matériaux d'un modèle de comportement de type Hyperélasto-Visco-Hystérétique. La méthodologie d'identification des paramètres matériaux est suffisamment simple pour être étendue à une large variété de polymères. Cette loi a pour but d'être utilisée pour vérifier la tenue mécanique en statique et en dynamique de structures dans le domaine de l'emballage alimentaire en PHA

Effect of natural weather on the structure and properties of polylactide/Cloisite 30B nanocomposites

International audienc

Effect of natural weather on the structure and properties of polylactide/Cloisite 30B nanocomposites

International audienc

Pectinase treatments on technical fibres of flax: Effects on water sorption and mechanical properties

International audienc

Prediction of interfacial behaviour of single flax fibre bonded to various matrices by simulation of microdroplet test

The microdroplet test is commonly used to determine the apparent interfacial shear strength (IFSS) of fibre-reinforced microcomposites. A deeper analysis of the test outcome can provide meaningful information about the fibre/matrix interface behaviour if a predictive approach is adopted. In this study, this predictive approach was used to investigate the quality of interface for polymer drops bonded single flax fibre at the microscale. Microdroplets of five thermoplastics matrices were prepared with single flax fibres. Microbond test was performed to assess the force–displacement curves of the studied composite systems. In addition, a finite element (FE) modelling methodology was adopted to quantify the interfacial role by proposing an interfacial constitutive law including the debonding stage. The numerical sensitivity results reveal the leading role of the interfacial stiffness as well as the fibre–matrix separation displacement in triggering the debonding behaviour. In addition, the numerical responses show strong matching with experimental trends using the proposed interfacial model for a wide variety of fibre/matrix interactions. The identification of the mechanical behaviour of the considered composite system shows that the best performing system is flax fibre/PLA, allowing a maximum fibre–matrix separation of 156 µm and an interfacial stiffness of 47 GPa/mm. The worst performing system is flax fibre/PP, which has a limited fibre–matrix separation of 55 µm. This study concludes that the proposed numerical model is able to capture the interfacial shear behaviour of polymeric drops bonded to a single flax fibre, which allows its extension at the mesoscale for a given arrangement of flax fibres in the bio-based composites