6533b7d9fe1ef96bd126be54

RESEARCH PRODUCT

Microstructure et vieillissement hygrothermique de composites renforcés de fibres de lin unidirectionnelles

subject

description

The current production of structural composite materials relies mainly on non-renewable fossil resources. Many regulations encourage the industry to move towards eco-friendly solutions. Within that general background, vegetal fibers appear to be an interesting alternative to synthetic fibers due to their good mechanical properties and their low density. However, using these fibers for structural composites is still limited because of their hydrophilic behavior which impacts processing, in-service properties and durability. The aim of this work is to study the effect of hygrothermal ageing, based on a sorption-desorption sequence, on the mechanical properties of flax fibers reinforced epoxy laminates. Among the processing parameters, the influence of the fiber conditioning and the thermocompression pressure were studied. Results show that it is necessary to control the fibers conditioning in order to produce a reproducible material with good mechanical properties. Optimized mechanical properties were obtained with a 3 bar pressure. Water sorption induced a plasticization of the laminate and the desorption revealed the reversibility of these plasticization phenomena, but also highlighted irreversible damage phenomena which altered the ultimate properties.