Failure Mode Analysis of Fique Fiber Reinforced Composite Using Computed Tomography Scans

Abstract

This study investigates methods to improve the tensile properties of fique fiber-reinforced composites by examining how failure modes vary based on resin and fiber properties. Two strategies are evaluated: using a flexible resin matrix with higher failure strain and applying mechanical treatment to the fiber fabrics. The baseline composite, made with untreated fique fibers and a rigid RTM polyester resin, exhibited premature matrix cracking as the primary failure mode. Replacing the resin with a flexible alternative increased composite strength by 28% and eliminated the multiple matrix cracking, achieving a single-fracture failure mode, as revealed by computed tomography (CT) scans. In contrast, mechanical treatment improved fiber alignment in the loading direction, resulting in a 76% increase in strength and stiffness. Despite retaining multiple matrix cracking as a failure mode, the treated composite reached a tensile strength of 111 MPa and an elastic modulus of 6.1 GPa—values among the highest reported for commercially available fique fabrics. Additionally, an in-situ CT scan analysis during tensile testing illustrated how multiple matrix cracking contributes to the composite’s non-linear response during the tensile test

Keywords: Natural fibers, Composite materials, Failure, CT scans, Fique