Experimental determination for interlaminar tensile strength of reinforced epoxy composites with flax fibers for L-angle specimens

The growing demand of laminated composite materials made of natural fibers and resins with a lower environmental impact in different applications requires a more detailed understanding about the performance during its service considering the delamination in curved parts are one of the most critical failure mechanisms. The present study focuses on an experimental investigation and calculation of the interlaminar tensile strength of unidirectional flax/epoxy laminated curved beams featuring varying thicknesses. The assessment is conducted through a four-point-bending test, in accordance with the ASTM D6415 standard, and the outcomes are subsequently correlated with the employed formulae. The study also involves an examination of the formulation and methodology applicability for the ILTS calculation of unidirectional flax/epoxy laminated curved beams. The analysis includes the impact on maximum interlaminar tensile stress and the evolution of delamination in the flax/epoxy laminated curved beams post-failure behavior. These findings have significant implications for accurately predicting the interlaminar tensile strength and post-failure behavior of such laminated curved beams.