The Tensile Fatigue Behavior of a Glass-fiber Reinforced Plastic Composite Using a Hybrid-toughened Epoxy Matrix

ABSTRACT: A thermosetting epoxy-polymer was modified by incorporating 9wt% of carboxyl-terminated butadieneacrylonitrile rubber microparticles and 10wt% of silica nanoparticles. The tensile fatigue behavior at a stress ratio, R 0.1 for both the neat-epoxy polymer (i.e., unmodified) and the hybrid-epoxy polymer was first investigated. The fatigue life of the hybrid-epoxy polymer was about six to ten times higher than that of the neat-epoxy polymer. Secondly, the neat- and the hybrid-epoxy resins were infused into a quasi-isotropic lay-up, E-glass fiber fabric via a ‘Resin Infusion under Flexible Tooling ’ set-up to fabricate glass-fiber rein-forced plastic (GFRP) composite panels. The tensile fatigue tests at a stress ratio, R 0.1 were performed on both of these GFRP composites during which the matrix cracking and stiffness degradation were routinely monitored. The fatigue life of the GFRP composite increased by about six to ten times due to employing the hybrid-epoxy matrix, compared to employing the neat-epoxy matrix. Suppressed matrix cracking and a reduced crack propagation rate were observed in the hybrid-epoxy matrix, which resulted from the various toughening micromechanism