Influence of strain rate and temperature on the thermomechanical behavior of flax fibers/ Elium acrylic composite: Experimental characterization and modeling
Résumé
Abstract This study investigated the viscoelastic behavior of unidirectional flax fibers/Elium acrylic composite reinforced with multiwall carbon nanotubes (MWCNT), focusing on their sensitivity to strain rate and temperature. In parallel, a cyclic tensile analysis was performed to monitor damage mechanisms in the composite. The results revealed enhanced mechanical and viscoelastic properties with increasing load and frequency. However, a reduction of 7°C in the relaxation associated to the glass transition temperature ( T g ) was observed, as measured by dynamic mechanical analysis, in composites containing MWCNT. The study also highlighted the strain rate and temperature dependence of the flax fibers/Elium acrylic composite. Damage analysis revealed that the inclusion of MWCNTs delayed the onset of damage in the composite, suggesting that MWCNTs enhance material strength and improve durability. Additionally, a new model, combining Richeton's approach with numerical modeling, showed good agreement with experimental data. Highlights MWCNTs improved fiber‐matrix interface in flax/Elium composites. Strain rate sensitivity, even with MWCNTs. MWCNTs raised storage modulus and shifted T g to lower temperatures. MWCNTs delayed damage, enhancing composite durability. The new model provides a good prediction of elastic modulus.