Fatigue in fibre metal laminates: The interplay between fatigue in metals and fatigue in composites

With the introduction of fibre metal laminates (FMLs) as a (fatigue) damage tolerant material concept in aeronautics, an interesting field emerged where fatigue damage interaction plays a dominant role. The hybrid concept effectively demands evaluating fatigue damage growth based on fracture phenomena typical for both metals and fibre-reinforced composites that continuously interact with each other. This paper explains current understanding of the fatigue fracture phenomena in FMLs, and it demonstrates how this interaction limits the criticality of both the metallic and composite fracture phenomena. In addition, it explains how the laminated hybrid configuration can be further exploited scientifically to unravel the physics of the individual fatigue fracture phenomena.Structural Integrity & Composite

Experimental study of temperature effect on the mechanical properties of GFRP and FML interface

Interface between laminates has always been the weakest part of bonded materials which is prone to delamination. This is even more prevalent in bonding of two different materials. The research aims to evaluate delamination of dissimilar materials under a range of temperature. This is a part of the experimental study to investigate the potential of fiber metal laminates (FML) to be used in high temperature environment. The mechanical response of interface of hybrid laminate was characterized at temperatures ranging from 30 to 110 °C. Double cantilevered beam (DCB) and end notched flexure (ENF) tests were conducted on glass fiber laminated aluminum specimens to obtain Mode-I and Mode-II delamination properties with use of data reduction. Mode-I fracture toughness (GIC) is significantly degraded by 59.45% at 70 °C and up to 83.65% at 110 °C. Mode-II fracture toughness (GIIC) only slightly degrades by 10.91% at 70 °C but drops rapidly by 82.84% at 110 °C