Mechanosorptive creep in single hemp fibres

Ousseynou Cissé (1) , Vincent Placet (1) , Lamine Boubakar (1)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)

The literature on the time-dependent behaviour of single bast fibres such as flax and hemp is extremely poor. This is however particularly important in view of the development of models able to predict the long-term behaviour of plant fibres and plant fibre composites (PFCs). So, the aim of this study is to characterise the creep behaviour of elementary hemp fibres, and particularly the influence of relative humidity on it. Single hemp fibres are shown to exhibit both instantaneous deformation and delayed, timedependent deformation when tensile loaded. The creep behaviour appears to be a logarithmic function of time with a high deformation rate during the primary creep and a lower and constant one during the secondary creep. The creep rate is also highly influenced by the humidity and humidity variations. Much greater creep in cyclic humidity conditions than in a constant environment at the high-humidity is observed only for high rates of relative humidity variation. This mechanosorptive effect is consistent with sorption-induced stress-gradient explanations.

Domaines: Mécanique [physics.med-ph]

Ousseynou Cissé, Vincent Placet, Lamine Boubakar. Mechanosorptive creep in single hemp fibres. Composites week @Leuven and Texcomp-11 Conference, Jan 2013, Togo. pp.1 - 7. ⟨hal-00993418⟩