Investigation of damage mechanism of flax fibre LPET commingled composites by acoustic emission

Tensile failure and fracture behaviour of parallel laid twisted flax fibre reinforced low melting polyethylene terephthalate (LPET) composites were investigated. The tensile failure results of the model specimens were compared with AE results in terms of amplitude, energy and counts. The failure results of the flax fibre LPET composites exhibited mainly matrix crack initiation as a brittle failure for low, medium and high fibre contents. Since the composites at high fibre contents have higher porosity content, they show higher strain to failure, higher variation in the tensile results and have different appearances on their fracture surfaces than those of the composites at low and medium fibre contents.